Do I have to say more? I think we've all had kombucha at some point, and it's one of the most well-known and popular fermented beverages. You can make it any flavor you want, it's supposedly very healthy and naturally carbonated. What more could you ask for from a drink? Kombucha is traditionally made from fermented black tea, but almost any liquid with enough sugar can be fermented into kombucha. For example, to increase the health benefits, some researchers and food scientists add Jerusalem artichoke tuber extract to produce the same metabolites as sucrose fermentation, with added inulin (prebiotic fiber) and fructooligosaccharides, a fermentable oligosaccharide (multiple sugar chains) that has been shown to be beneficial for gut microbiota. Kombucha is an example of cooperative fermentation using a SCOBY (symbiotic colony of bacteria and yeast), which as a collection of microbes first convert sugar into alcohol, then into acetic acid (HC2H3O2). The specific variations of microbes vary, but the most common organisms are yeasts, unicellular fungi, and acetic acid bacteria (AAB). The yeast present is often saccharomyces cerevisiae, but the SCOBY can include many of its relatives. Often several strains of AAB might be present, but some variation of Gluconacetobacter or Acetobacter will usually be present: however, according to an analysis of the metabolic byproducts of kombucha, the main acids present are acetic, gluconic, tartaric, malic and citric acid. The relationship between AAB and yeast can be described as commensalism: the bacteria benefit more from the yeast, but saccharomyces tolerates acidic environments and is not significantly affected. But how is the SCOBY created and why is it solid?The bacteria and yeast live on a structure called a zoogleal mat: as they multiply and propagate, they excrete cellulose, forming a sheet that floats on the liquid. As the mixture ferments, the mat grows, spreading to the edges and then increasing in thickness, creating the solid formation that appears on the surface of kombucha. Living on the mat allows the AAB to be in direct contact with the air above the liquid needed to undergo alcohol fermentation, which also allows the bacteria to metabolize and create a stronger cellulose network. Once introduced to a sugary liquid, the yeast in SCOBY begins fermenting by consuming simple sugars and producing alcohol and CO2 as a byproduct. The AAB then ferment the ethanol by oxidizing it into acetic acid, using the oxygen available in the environment. According to The Noma Guide to Fermentation, “As a rough guide, under ideal conditions, yeast typically ferments 2 units of sugar into 1 unit of alcohol, and AAB converts 1 unit of alcohol into just under 1 unit of acetic acid”. Vinegar is made in a similar process with one distinction: vinegar is a 2 stage fermentation. First, yeast converts sugar to alcohol, and some strains have different tolerance for alcohol and will die off once that level is met or they are killed by pasteurization. In the second stage, AAB ferments alcohol into acid, but without the yeast, bacteria will eventually run out of fuel and the fermentation will stop. In contrast, Kombucha is a sustained fermentation: yeast continually ferments sugar into ethanol for the bacteria to convert into acetic acid, so the beverage will continually become more and more sour until all available sugar is consumed. Thus, it is crucial to control when the kombucha is bottled, how it is stored and how quickly it is consumed so the ideal sweetness and acidity is achieved. SCOBY thrives in a slightly lower pH environment, with an optimum temperature in the range of 77 to 90˚F. In order to prevent wild fungal molds like Aspergillus, which can produce water-soluble toxins, you need to backslop with some kombucha from the first batch as with other ferments to establish an ecosystem. However, the sweetness is crucial in the making of kombucha, as too much can induce a higher production of acetic acid and alcohol than desired and too little will not produce enough sweetness or fermented flavor. Thus, the degrees Brix (Bx) measurement of the amount of dissolved sucrose as a percentage of the total solution is critical to calculate the ideal sweetness and fermentation of kombucha. The Brix measurement is calculated using the specific gravity of the solution: ratio of the density of a solution to the density of normal water. The higher the density of sugar, the higher the brix measurement. Degrees brix can be measured with a refractometer, which measures the way the solution refracts light as sucrose changes light refraction. Noma has determined for their restaurant that 12˚˚Bx is an ideal concentration of sugar for the desired sweetness and acidity, but it varies based on the desired result. Kombucha historically originates in Northeast China or Manchuria around 220 BC, and it was initially prized for healing properties. The name stems from Dr Kombu, a Korean physician who brought the drink from China to Japan as a cure for Emperor Inkyo (hence the name: cha = tea, kombu being the name of the doctor). Despite its decline during WWII because of a lack of tea and sugar, the beverage regained popularity in the 1960s due to a Swiss study showing health benefits comparable to yogurt. However, many attribute the widespread growth of kombucha's popularity to GT Dave, the brand that started in 1995. The fermentation movement during the 90s also helped the beverage gain national popularity, cementing it as a supermarket staple rather than just a niche drink. Kombucha production has had its ups and downs: regulatory issues arose in 2010 when it was discovered that during the second fermentation producers were not monitoring ABV levels in the bottles. Thus, the kombucha could be anywhere from 0.5% to 2.5% ABV (for context, some beers are 3.0%). It was withdrawn briefly from stores until the Alcohol and Tax Bureau established regulations for minors on higher than 0.5% beverages. Safe to say that many people drink kombucha and some dismiss its health claims because of the sugar content, but it's actually really good for you. Kombucha is considered a superfood, as one serving gives 20% of daily B vitamins and 25% of daily folic acid (B6). Research has demonstrated a clear antimicrobial activity against certain pathogens in the body, largely due to the presence of catechins and acetic acids. Phenolic compounds were also shown to increase over fermentation period in the kombucha, increasing the antioxidant profile of kombucha, which was already high due to tea polyphenols, ascorbic acid and DSL. Kombucha has even been shown to protect against hepatotoxicity induced by various pollutants. Tea fungus in particular, the biomass produced as a film on top of the kombucha has been shown to be extremely beneficial for health, as it is rich in crude fiber, protein, and amino acid lysine. There are claims that it is beneficial for gut microbiota, but those are yet to be proven: even so, it likely aids in establishing some good bacteria on the surface of the gut, so it may have some residual effect. Kombucha is obviously consumed as a beverage, but the SCOBY is also candied in the Philippines and eaten as a sweet called nata. The candy is often made from the cellulose byproduct of vinegar since they produce so much in the Philippines, but kombucha can be used in the same way. Kombucha can also be used to cook with as a seasoning, and its uses are varied in the pastry world, but the possibilities are broader than you might imagine. Noma uses kombucha as part of the beverage pairing for their meals to compliment the flavors of the dishes, and they add native ingredients like sea buckthorn and rose hips to reflect the Nordic climate. I won't tell you to try it because likely you've had kombucha already, but I encourage you to find more creative ways to use it. Use it in salad dressings, as part of braises, marinating liquids, cake soaks, really anything!
0 Comments
Mirin is amazing - it's hard to go back once you start using it. The uses for the sweet wine are numerous, from desserts to braising, mixing in sauces, marinating, you name it. It is also one of the core pillars of Japanese cooking, along with sake, dashi, soy sauce and sugar, but it's not really consumed as a drink in the same way as sake is. The differences between sake and mirin are distinct: mirin is usually sweeter and less alcoholic, with a 14% ABV (alcohol by volume) profile. Sake as aforementioned is also consumed as a drink, whereas mirin is usually not, and sake is added earlier in the cooking process to evaporate some of the alcohol. Mirin is made by steaming mochi rice(glutinous rice), and mixing it with malted rice, a backslop of alcohol (either shochu, a spirit distilled from potatoes or sake), aspergillus oryzae, and rice koji. There are 4 categories of mirin: 1. Hon mirin (true mirin): This version contains 14% alcohol and no salt. It is made from steamed glutinous rice, rice koji, aspergillus oryzae and shochu, and it is fermented at 20-25 degrees celsius for 40-60 days. 2. Mirin: This version uses sake instead of shochu, and it is easier to come by in the US 3. Mirin-like condiment: It contains 8-14% alcohol and 2% salt, and is composed of starch syrup (rice or corn), water, alcohol, rice and salt. 4. Mirin-type condiment: The most commercial version, it contains no alcohol, and mimics the flavor of hon-mirin. It is made of starch syrup, brewed rice cultures, vinegar, and acidic components. It was manufactured by food conglomerates in Japan to bypass alcohol taxes and to mass produce, but it is also good for Halal Japanese cooking and for those who do not consume alcohol. Unlike sake, the process of producing mirin does not involve yeast, as aspergillus and the enzymes present do most of the work. The enzymes in koji cause the saccharification of amylopectin and amylose starch chains in rice, breaking them down into glucose and fructose monomers, and proteins are also hydrolyzed into amino acids and organic acids, creating volatile compounds that add to mirin's fragrance and flavor. According to an analysis done by Japanese scientists on the profile of mirin, there are at least 100 volatile compounds that have been identified such as ethyl ester groups, strecker aldehydes and phenolic acids, some of which are beneficial for your health. Mirin is traditionally used to mask fishiness and gaminess or to bring out the natural sweetness of ingredients. It is an integral part of real teriyaki sauce, and is usually the base for sukiyaki, a sweet broth that is used to cook sliced beef and vegetables hotpot style. The form we consume has been around for at least 300 years, but it was originally consumed as a sweet liquor during the Ashikaga shogunate (1467 to 1603). However, it would spoil easily so it was distilled into a wine with a higher alcohol percentage, and that is the version used today. It is similar to the fermented glutinous rice wine produced all over China, but the way it is used and its alcohol content separates it from their version. Mirin is an integral part of Japanese fermentation culture, and apparently there is even a holiday for hon mirin every year on November 30th. A lot of chefs use mirin religiously: one restaurant in particular based in Taiwan makes a poached egg dish where they marinate the eggs in mirin and sake, and make a corn potage (one of the French varieties of thick soups made using cream) using the wine as well. Mirin is also commonly used at ramen restaurants as well as an addition to the tare (seasoning), or as an addition to sushi rice. As to making it, that is up to you whether you want to homebrew (I don't publicly endorse anything haha don't come after me). In my opinion, making it could as long as you are of age could help improve your cooking, and provide another use for rice. It's also quite healthy as a natural sweetener due to its amino acid profile. However, another more practical reason might be that mirin in the US is quite expensive, especially the real kind (hon-mirin and mirin): one 10-oz bottle from Eden foods, one of few companies producing mirin without additives costs around 14.99. It's also not easy to come by, as the only supermarket I have been able to find non-commercial brands is at Whole Foods of all places. Whether you decide to make it or not, it's worth looking into as a staple pantry item - I use it in almost every dish. Hi everyone, In light of the current situation, I would like to share my thoughts on how fermentation can be of practical use to you. These are strange times indeed: the world seems to be in the middle of a wave of fear and pandemonium that appears not to have a definite end, and our lives as we know it have been compromised to protect our overall well-being. Statistics are unclear, and the media has misinformed the public through their alarmist rhetoric declaring national emergency and flashing headlines of death and misery. What does all of this mean for you and me? As you might have noticed, it is becoming increasingly difficult to buy certain foods at your supermarket, as they are out or have been limited for people to a certain amount of items. Fermentation can be of great use to you all right now, as you may want to extend the shelf life of certain foods or preserve them for future use. Before anything else, fermentation was initially a survival strategy, used during periods of famine, disease and war, which is exactly what we seem to be going through. Although the previous description refers to a more extreme scenario, it would be wise to consider how to store some of your ingredients, i.e ferment them, so you can use produce or any other ingredient for longer and waste less. With that being said, I would like to continue posting regularly on the blog, with the understanding that some of you may be less inclined to try these recipes, which is perfectly ok. However, I do suggest that you at least attempt some of the easier ones, as you may be surprised how much you enjoy having it in the house. **** Back to regular scheduled programming: on the agenda today is black garlic. Black garlic is a bit of an anomaly: it's not technically a fermented product, because no micro-organisms are present in its transformation, but it is preserved in similar ways and transforms the original ingredient into a shelf-stable item. So you might ask, then what is black garlic? It's basically garlic that has been held at a very low temperature for a long period of time, sufficient to catalyze the Maillard reaction and dehydration. In other words, it caramelizes very slowly, over the course of 3 weeks or so. Black garlic gets its color partly from chemical reactions such as pyrolysis, caramelization and Maillard, which are non-enzymatic, but some of the browning is caused by natural enzymes in the garlic. Polyphenol oxidase in particular is responsible, a compound key in maintaining a plant's health: once the flesh is exposed to oxygen, the enzyme alters phenolic compounds and produces melanins which turn the plant brown. While these products serve as antibacterial agents, in this case they darken the garlic. These enzymes are also responsible in part for lowering the pH of the garlic, which decreases from around 6.33 to 3.74 over the course of 30 days. In addition, the Maillard reaction, an enzymatic process of reducing sugars and amino acids is responsible for part of the transformation; thermal decomposition of organic compounds in the absence of oxygen, or pyrolysis produces a wide range of flavor compounds . Unlike fermented foods, black garlic is held at 140 degrees Fahrenheit, a temperature unsuitable for any microbes but high enough to catalyze reagents reacting with one another. Contrary to popular belief, the Maillard reaction can still occur at such a low temperature, because temperature is define as the average motion of billions of molecules, and even if a few molecules move fast enough to cause a Maillard reaction, they eventually add up and cascade. The Maillard reaction is classified as a redox reaction, short for reduction-oxidation, where electrons from the compound are donated back to their original owners (see Figure 1). It was discovered by Louis Camille Maillard in the early 20th century, who found that when food is heated, sugars like fructose and glucose or those bound in starch take place in redox reactions with other free amino acids or those bound in polypeptide chains. This process causes highly unstable intermediary products to form, as shown above in Figure 2 that further break down, creating volatile flavor compounds and a certain “browned” characteristic. The reaction is also coupled with dehydration, where more free water is released to the environment when amino acids and sugars hydrolyze. Different flavors develop depending on the type of amino acids present, and most Maillard reactions take place at temperatures above 239 F where there is enough kinetic energy to force the reagents to react. Dehydration promotes the Maillard reaction, because water prevents the formation of certain compounds and due to its high specific heat capacity absorbs a lot of heat energy, keeping the temperature at its boiling point. However, given enough time Maillard can occur in hydrated environments as aforementioned, because reactions will eventually cascade. Garlic is particularly suited for blackening for the following reasons:
“Extensive in vitro and in vivo studies have demonstrated that ABG has a variety of biological functions such as antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-allergic, cardioprotective, and hepatoprotective effects. Recent studies have compared the biological activity and function of ABG to those of raw garlic. ABG shows lower anti-inflammatory, anti-coagulation, immunomodulatory, and anti-allergic effects compared to raw garlic.” Because certain compounds are preserved through lower temperature exposure, black garlic retains much of its beneficial nutrients, without the pungency of consuming it raw. I would describe the taste as almost sweet like candy, with caramelized onion notes and a subtle roasted garlic finish. I often use it in braises to up the umami factor, or blend it to make a puree or paste for a dish, but there are really so many uses! It is becoming more available in stores (although I don't know now with the Coronavirus), but many Chinese stores carry the Chinese variety of garlic with one bulb that has been blackened. I highly recommend you try it! Hopefully when all of this madness is over, we will be able to return to some semblance of normalcy in our routines. However, we have to be positive and look for things that we can to do occupy our time, and fermentation fulfills this need while helping you stay healthy. Maybe you can't find black garlic right now, but please consider making your own ferments!! I've been waiting to make this post for a long time. Kimchi is one of my absolute favorite foods, never mind just fermented products. I go through a whole jar pretty much every week, and I have gotten to the point where my fridge downstairs is a storage for kimchi (what most Koreans use their second fridge for exclusively). There are over 200 varieties of kimchi!! They range from salty to sweet to mild to spicy, and they can be made traditionally or from non-traditional ingredients. Paired with meat, or soup, or literally anything savory, it takes the dimensions of flavor to another level. Kimchi's really amazing, I cannot say enough good about it. According to the sikyung, a Korean historical document, kimchi was invented around 4000 years ago as a method of preservation for vegetables. Kimchi is derived from two Chinese characters for salted vegetables, as it originates from China, but what distinguishes it from Chinese ferments is the short incubation period. It was traditionally made in onggis, traditional earthenware which housed beneficial microorganisms within its walls and helped the fermentation process begin. Kimchi can be classified into 2 types: seasonal and winter, where the method of preparation depends on vegetables available at the time and different seasonings. Kimchi can also be subdivided by temple style and generic style, where the former prohibits the use of alliums such as scallion, garlic and onion. For example, dongchimi radish kimchi is one type without gochugaru that is made during kimjang, the UNESCO dubbed event of making kimchi. This particular kind contains a smaller amount of salt than normally used, as to achieve higher levels of fermentation. Even Northern and Southern kimchi differ by the use of beef broth in winter kimchi, instead of seafood. Contrary to popular belief, not all kimchi is red, as white kimchi, or mul kimchi is very popular as well. There are several theories on the origin of pepper in Korean cuisine, or when kimchi started containing gochugaru, but the idea that before the 1600s there was no red pepper does not hold weight according to a large body of research on the history of kimchi. Perhaps it was less prevalent and white kimchi was more common, but there are several practices dating back to the 13th century and earlier detailing the use of red pepper in kimchis. Despite the differences between the kinds of kimchi, it is a lacto-ferment, as the primary cultures within it are in the lactobacilli genus, and the type of fermentation produces lactic acid as a byproduct. According to one PubMed study on the electrophoresis of a generic kimchi's macrobiotic community; “Pediococcus pentosaceus, Leuconostoc citreum, Leuconostoc gelidum, and Leuconostoc mesenteroides were the dominant bacteria in kimchi. The other strains identified were Tetragenococcus, Pseudomonas, Weissella, and uncultured bacterium”. Another source on the history of kimchi says that Leuconostocs, Lactobacilli, and Weissella are the main types of bacterial cultures, but experts agree that Weissella is more present in kimchis with gochugaru (Korean chili powder, see image above) present. It is interesting to note that the type of bacteria present affects the quality of the kimchi, as according to research done by Korean academic scholars on kimchi profiling, “L.mesenteroides is the important microorganism responsible for kimchi fermentation, whereas lactobacillus plantarum, which is considered to be responsible for making sauerkraut, deteriorates the quality of kimchi”. So not every lacto ferment relies on exactly the same strains of bacteria: diversity is critical to the survival and taste of a ferment! In kimchi, CO2, organic acids, ethanol and many other metabolites contribute to the flavor profile along with certain amino acids from fish products such as anchovy sauce (like in my last post) and brined, salted shrimp. Many of the compounds derived result from the unique fermentation process, as Kimchi is normally fermented less than other types of preserves, with an incubation period of 3 days. It only needs this time period because the growth of LAB cultures accelerates with the presence of additional starch from the added porridge of glutinous rice flour and amino acids, and it is traditionally consumed at a certain maturity. The ingredients in kimchi play a crucial role in the shelf life of the ferment: for example, Gochugaru deters harmful bacterial growth and promotes LAB cultures. Garlic, ginger and scallion all act as antibacterial agents, and salt's osmotic ability reduces the water activity so that spoilage is less likely to occur, and fewer bacteria can survive in the environment. Fermented seafood and meat ingredients also contribute to the strength of the microbial community in kimchi by acting as a back slop, where beneficial cultures are already introduced into the mixture prior to fermentation. They also provide amino acids for certain bacterial strains to consume, and thus establish a strong microbial community. There are usually 4 stages to kimchi making: brining, seasoning, fermenting, and storing. First, the vegetables are either submerged in a brine to remove excess moisture or salted and forcefully mixed to achieve the same result. Then, seasonings such as garlic, starch porridge, rice syrup, ginger, red pepper, anchovy sauce, scallion and brined seafood are added and thoroughly mixed by hand. Traditionally Koreans did not use much sugar in their cooking, so starch was used for saccharification purposes along with brown rice syrup for some sweetness. The addition of red pepper powder supposedly increases the diversity of microbes within the ferment, which prolongs the shelf life of kimchi, but it is not required as aforementioned. The kimchi is then fermented at ambient temperatures of 65-70 degrees Fahrenheit, relying on spontaneous bacterial growth. Higher temperatures as mentioned above help to accelerate fermentation, while the range 40 to 55 degrees slows it down to and affects the rate of metabolic compound production (Note: if you decide to make kimchi [which you should], don't be discouraged by discoloration, as it may indicate that your batch has oxidized, but not necessarily spoiled). Kimchi is then stored for the winter months underground in the onggis for up to six months, and even a year, and depending on the season the jars are then unearthed. Kimchi making is an art: it relies on native microbial community for fermentation, so it is incredibly difficult to mass produce. It is also the national dish, however, and when Koreans travelled on Apollo XIII, scientists developed a portable version that did not contain live cultures but had some of the same flavor profiles so that they could eat it in space! It is an integral part of the culture, and as such families pass down their respective recipes, some of which are guarded heavily to the next generation. There are even a few individuals in Korea who are certified as living national treasures in kimchi making! Kimjang is so important in Korean culture that it has been certified as a UNESCO world heritage tradition in fermentation, where families and the community come together to make kimchi a few times during the year. As beautiful and intricate as kimchi making can be, it doesn't require the same complexity at the home level, and it can be one of the easiest ferments to make. It's basically a less fermented version of sauerkraut, and can even be eaten non-fermented as a seasoned vegetable side dish. There are SO many uses for kimchi, and it is delicious once you get past the smell. Honestly, I like the smell because I am used to it by now, nor did it really bother me to begin with. The images above are an idea I had for deconstructed Korean barbecue, where bulgogi meat is usually paired with a series of banchan, or smaller side dishes and kimchi. You can use either beef or pork, but I don't recommend chicken for this recipe, as it doesn't stand up quite as well to the strength of the flavors.
Braised Pork, Kimchi Foam, Kimchi and Sweet Potato Ingredients: - 2-3 oz braised pork - 1/2 tsp sesame oil - 1/2 tsp soy sauce - 1/2 tbsp gochujang (Korean fermented chile paste) - 1 tsp rice vinegar or persimmon vinegar, traditionally made in Korea - 1 tsp mirin(fermented glutinous rice wine) - 1 sweet potato, roasted in the oven in foil at 350˚F for 1 hour or until completely cooked through - 2 tbsp combination of EVOO + ghee - 200 ml kimchi brine - 1.6 g xantham gum or 2 g gelatin - Homemade kimchi (there are so many recipes out there, use them!) - Microgreens or finely julienned scallion greens Method: 1) If using xantham gum, shear gum into kimchi brine using a high speed blender until completely immersed. If using gelatin, dissolve into kimchi brine for about 5 minutes, then heat on low until completely dissolved. Transfer to an iSi whip, load with 2 cartridges NO2 and refrigerate for at least 4 hours. 2) On medium heat, heat the oil and ghee until smoking. Form a 2 x 4 inch rectangular slice of sweet potato using a knife, and place gently in the oil. Baste while cooking and try to get as even a color as possible. Once browned, take out of pan and transfer to a plate lined with paper towel, and season with smoked salt. 3) Mix the pork with the ingredients above; the pork should ideally be warm for serving. 4) To plate: using a ring mold, portion the pork onto a dish, and then lay the potato slice next to it. Decorate with some kimchi, a few pinches of microgreens. Shake the canister about 5 times, then pipe some of the kimchi foam out. Enjoy! There's a lot more to soy sauce than this bottle. Soy sauce is one of Asia's greatest culinary exports: it's used in so many cuisines today, and it represents a positive side of globalism that wouldn't exist otherwise. However, soy sauce is widely misunderstood as something to pour over white rice (don't do that please) or Chinese takeout food, but it hasn't reached national awareness yet that it can be an artesanal product just like beer and wine. It is one of the most complex, intricately flavored ferments in existence; sustainable and environmentally friendly; and it's relatively inexpensive. The English word soy comes from the Japanese term shoyu for soy sauce, which originally stems from Chinese jiangyou , or literally oil on the surface of bean paste. Shoyu is one of the most complex fermented foods, as it involves aspergillus oryzae molds, LAB, and yeasts in two distinct forms, all of which have different metabolisms and byproducts. There are two main types in Japan: tamari, which is made with soybeans alone, and shoyu, which contains wheat and soybeans. It's easy to confuse miso and soy sauce in their process, as soy sauce was originally invented from the miso making process, but the difference is that aspergillus oryzae is grown upon grains and the soybeans, whereas miso has just the grain inoculated. This diversity of substrate fermentation causes in the words of Sandor Katz a “formation of more complicated metabolic compounds, a higher degree of protein hydrolysis and liquefaction, and the production of much sharper and stronger flavor in shoyu than in miso”. Soy sauce is essentially the liquid on top of the bean paste. This fluid appears on the top for 2 reasons:
OnThere is some controversy around consuming soy products, as it is supposed to raise estrogen levels and cause hormonal abnormalities. However, most of the health problems like the antinutrient isoflavones in soybeans can be negated by fermenting them, and many complications arise from consuming the beans raw. All cultures that consume soybeans traditionally ferment the beans first for this reason, to remove saponins and indigestible compounds that inhibit nutrient absorption and irritate the stomach lining. The process of making soy sauce starts with the soybeans: usually they are boiled because they don't cook properly when steamed. Thus, wheat acts as a mediator of moisture, and another source of starch upon which the mold can act upon. In the first stage, the soybeans and toasted wheat are combined with the aspergillus and left to ferment for about 3 days until a mycelium coating has formed around the outside. It is then poured into a salt brine, around 6% and fermented for a minimum of 6 months, and many traditional ferments age from 1-3 years. Soy sauce can also be aged in barrels like alcohol to develop cask flavors, like Bluegrass soy sauce in Kentucky (see above picture) or smoked soy sauce, but it's usually fermented in a large cedar vat called a kioke . According to the book Culinary Treasures of Japan on the role of koji, or inoculated rice in soy sauce: "[E]nzymes from the koji and the naturally occurring yeasts and bacteria slowly breakdown the complex carbohydrates, proteins, and oils of the wheat and soybeans into sweet sugars, aromatic alcohol, and flavorful amino and fatty acids.” The mash that forms is then called moromi, and once all of the shoyu has been extracted from the top layer, it can be sold to farmers as animal feed. On a side note, this is actually a half-decent idea for some of our excess soybean reserves: it's such a huge cash crop, yet a good portion ends up as animal feed, completely unnatural, or soybean oil, which damages the environment in its production methods. Why don't we direct some more of these soybeans towards human consumption rather than feeding cows soybeans? (insert thinking emoji here). Obviously it's not that easy, but just a thought for consideration. Nama shoyu, or raw and unpasteurized shoyu is considered to be the best quality and healthiest type because of its organic molecule and amino acid concentration, as well as the presence of beneficial microbes. However, there are many different kinds of soy sauce outside of Japan as well: in Indonesia, they produce this: Kecap Manis (pronounced ked-chap mahn-iss) is fermented with palm sugar, clove and anise, and then reduced to a sweet and syrupy consistency. In Vietnam and Thailand, there is tuong, made from toasting soybeans first, lacto-fermenting them, and then inoculating with aspergillus. You get the message - China has around 5 or 6 varieties, and don't get me started on Japan: Unfortunately, many of these varieties are produced commercially or replaced by commercial products. Commercial shoyu is manufactured by the acid hydrolysis of defatted soybeans, i.e after they are extracted for oil, and it does not involve fermentation. Acid hydrolysis extracts free amino acids from the proteins by using HCL (hydrochloric acid) and warm temperatures to break down the vegetal matter, then neutralizing the mixture with NACO32-(sodium carbonate). The reaction yields salt, an organic sediment called humin, and hydrolyzed vegetable protein (HVP), which is supposed to taste like meat broth, thanks to the amino acids threonine. Unsurprisingly, the result is less attractive in aroma and flavor because of “the lack of aromatic substances such as esters, alcohols, and carbonyl compounds which are derived from the fermentation process”, according to the Journal of Industrial Microbiology. Some countries use a mix of both processes, but fermentation is the best way to go for flavor. Japan has pushed back against this complete industrialization: according to the Soy Info center, “In 1963 the Japanese Ministry of Agriculture and Forestry ( Norinsho), with the support of the Japanese Shoyu Association, set the first Japanese Agricultural Standards (JAS) for shoyu; fermented shoyu was still allowed to contain up to 80% HVP. By 1964 HVP constituted only 30% of Japan's total shoyu volume and 20% of the total was still semichemical shoyu”. Although Kikkoman and many of the commercial brands are Japanese, traditional fermentation is still the preferred method of preparing soy sauce. This is in part due to the advances made in the 70s:
Alright, so this one's not the prettiest. However, it may have great ramifications for our future consumption of meat, as supplies will dwindle and we will need to extend its shelf life without refrigeration. Our ancestors didn't have access to fridges, so they had to preserve meat in a number of ways: by curing, salting, drying and fermenting. One of these methods was to make garum, an ancient animal protein sauce considered to be the mother of all modern condiments. It is thought to originate from North Africa around the 500BC mark in present-day Tunisia, and was also popular with the Carthaginians; however, the Romans are credited with the discovery of garum itself, which they used with fish. In the Roman kitchen, garum sauces played a crucial role in the flavor profile of dishes: one such condiment was called oenagarum, a wine and fermented meat sauce widely used. There were many names for garum, such as liquamen, referring to the properties of the final sauce, but the idea is the same: take raw animal protein, add salt and let sit for a while. Sounds simple enough, right? Well, it is and it isn't, because fermenting animal proteins is a little more dangerous. Since meat and fish flesh are almost entirely protein and fat, devoid of any carbohydrates, the usual materials that support positive bacterial growth aren't present, so the risk of contamination by dangerous microbes is higher. Especially during slaughter, when the interior flesh is sterile and then exposed to a multitude of microbes, decay and putrefaction can occur in addition to fermentation, spoiling the final product. Thus, heavy salting is crucial to prevent organisms like Clostridium Botulinum: no less than 25% by weight in many recipes, although 10% is enough according to the International Handbook of Foodborne Pathogens. The water activity measurement, or how tightly the water is bonded to the product and how much free water there is, can be used as a tool to determine the conditions for which certain microorganisms grow. Because the water molecules are sequestered by the sodium ions, microbes cannot use them for their life functions, and thus the higher the salt concentration, the lower the number of organisms that can live within the solution and the less hospitable it is. Most bacteria need a water activity environment of more than 0.9 to grow although fungi can withstand levels above 0.7. This explains why salting is crucial to prevent bacterial and microbial contamination: according to Sandor Katz, “C.Botulinum, for example cannot grow in an environment without a water activity (aw) measurement below 0.94, while inhibiting Listeria monocytogenes requires a drier environment, below 0.83aw." Salt also inhibits certain microorganisms and enzymes from degradation; however, percentages of salt may vary depending on what other methods are used to preserve or ferment the meat (i.e acidification, smoking, curing) rather than the production of garum. The flesh of all animals contains proteolytic enzymes that contribute to autolysis, an enzymatic digestive process where the entire organism is consumed by its own biochemicals, and hydrolysis, where amino acids degrade from their polypeptide structures. Autolysis might sound familiar, because it sound like sourdough's initial rest period before mixing, but it's not the same. Although all of us also contain these enzymes, usually they are stored in cell components known as lysosomes, which are broken down as salt penetrates the cell membrane and the proteins degrade. For example, fish protein hydrolysis is primarily catalyzed by enzymes present within the viscera of the fish and their organs, but it doesn't occur until after rigor mortis has set in and the fish has been left to sit. This is why the mixture of proteins are usually left out for 24-48 hours prior to salting, as the fermentation process is jumpstarted and certain microorganisms are pre-selected in the environment. However, as aforementioned, salt is necessary, as it both expedites autolysis and safeguards against harmful microbes. No water is added, as salt pulls moisture from the fish cells through osmosis. The number of bacteria present in the solution slowly decreases as the salt is added, although halophilic (salt-loving) bacteria likely play an integral role in the flavor development according to the Noma guide to fermentation. Salt is also key to enzyme function, as they need to be suspended in a liquid medium to function effectively, otherwise they won’t float from one protein chain to another and break them down into amino acids. Along with salt, heat also precipitates enzyme reactions, which explains why ferments were left out in the sun to accelerate the fermentation process. When made properly, garum is quite delicious because of its umami, or the glutamic acid components present within the solution. The proteolytic enzymes free glutamic acid, which then reduces to become glutamate (C5H8NO4), and then binds to mineral ions like sodium to form monosodium glutamate (MSG), the same compound found in many processed foods. Just goes to show that it is in fact entirely natural. We feel sated sooner and longer when we eat a high-umami meal, because we have glutamate receptors in our gut that signal when we eat these foods, and we also are hardwired to seek them out. Ever had a bowl of pho and feel deeply satisfied, whereas with some other foods you might not? Part of that is due to the fish sauce that goes into the broth. Although it doesn't look or smell great, often times there is a misconception between actual rotten meat and fermentation. For example, the odor of“fishiness” indicates the spoilage of the fish flesh and fat, but it doesn’t occur in strictly fermenting sauces. Garum has experienced a sort of culinary revolution as chefs look back to old techniques for flavor production and ingredient preservation. It has become a critical component of mayonnaise, stock and other seasonings, and it's even present in condiments some of us might consume daily, like Worcestershire sauce! At Noma, they have revolutionized the process of garum making by fermenting animal proteins with warm water, salt and koji, the innoculated rice with the goal of autolysis only. This is actually quite ingenious, as koji takes advantage of the protease enzymes to speed up autolysis, and Noma uses Aspergillus Sojae, which produces more proteases than the other strains. So maybe you don't want to make this one at home, understandably because of the smell and the yuck factor, but consider incorporating it into your food if you consume meat products as a sustainable method of preservation. It's quite healthy, due to the vitamins and minerals present within the organs, and the high concentration of amino acids. It's one of those seasonings where if you incorporate it into a dish, it makes the final product shine, but on its own it may not taste amazing. However, don't be discouraged; give it a try, and who knows, you might already be using garum.
Alright, enough said. Flour, water and salt; it doesn't get simpler than that. Or does it? Bread is actually fascinating, and it's one of the most well-documented types of fermentation due to its popularity. There are SO many kinds out there, from the sourdough pictures above that I made to rustic rye bread in Iceland that's baked under geothermal vents. Most bread is leavened, i.e there is an agent that allows it to rise and traps gas within the dough, making the texture lighter. However, I am focusing specifically on naturally leavened bread, made with a starter. The fermentation of bread was originally a chance contamination of aerial yeasts, and the first documented leavening agent was in Egypt, where beer froth was used. However, for most breads after this period, the leavening agent was a piece of leftover dough with yeast already growing within, hence the term "backslapping". Bread represents the culinary domestication of grain, according to Harold McGee, as humans figured out how to make the humble grain more nutritious: release certain vitamins and minerals through the fermentation process, and cook the grains so that we can digest them through baking. According to a NCBI article, sourdough bread increases the presence of 118 bioavailable compounds, including BCAAs, phenolic acids and certain phytonutrients, and is thought to have a lower insulin response due to the digestion of certain sugar-conjugated acids and other macromolecules. Bread contains both alcoholic and lactic acid fermentation, but the yeasts, namely Saccharomyces Exiguus (not Cerevisiae surprisingly) is responsible for the majority of metabolic activity within the dough. The “starter” is a mix of flour and water which is left to ferment at room temperature, and which ambient yeasts feed off of. It is hard to keep different starters from “deteriorating” when bringing them into a new environment, as the changing microbial content affects the microflora. This is thought to be the reason why you can't bring San Fran starter culture to Chicago, as the environment is simply different. The best bread relies on slow fermentation, as yeast metabolization creates carbon dioxide gas, which becomes trapped in the matrix of gluten proteins that coagulate. It also unlocks flavor compounds and starts the saccharification process (starch is broken down into its constituents), where the bread tastes sweeter. If the yeast activity is prolonged at colder temperatures, the theory goes that it has more time to digest the starches in the flour and increase the presence of lactic acid within the dough. It is thought that starters that have been maintained for decades are resistant to contamination, as they are believed to have some antibiotic properties, like penicillium. Since the community of micro-organisms has been established for a long time, another plausible explanation is that the niche is more stable in its relationship with the yeasts and bacteria. C6H12O6 → 2C2H5OH + 2CO2. That's it effectively: glucose is broken down into carbon dioxide and alcohol. The yeast Cerevisiae has a preferential metabolism: single unit glucose and fructose monomers are the first to be consumed, via the flour, and then it switches to the disaccharide maltose, which is derived from the starch granules’ saccharification process through enzymes. Interestingly enough, Exiguus, the yeast in sourdough is unable to break down maltose, and it thrives in very acidic environments as opposed to Cerevisiae. The sour taste in bread is about 75% lactic acid, and 25% acetic acid, the majority of which is produced by the yeast, but some strains of bacteria are involved. They are all closely related, but not to any other known species; thus, they are called Lactobacillus sanfrancisco, and they function best at a temperature of 85˚F and a pH between 3.8 and 4.5. Yeast performs best at 95F, and it has a requirement of warm water (105˚ to 110˚F) for rehydration, as lower temperatures result in a loss of its fermentation power. Its behavior isn’t completely understood; it is thought that residual carbohydrates in the dry yeast cells must be reconstituted through cell membranes rapidly enough so that crucial cell contents are not lost to the solution. Added sugar also affects the yeast metabolism rate, increasing the rate of activity until it has an osmotic effect on the cells, releasing water and then retarding yeast concentrations. Thus, extra yeast is required in sweetened breads, because metabolic activity declines sharply due to osmosis, which is the same with added salt. Fermentation plays a crucial role in the strength of the dough, other than gas production: the acids are important for strengthening the gluten network, as they encourage coagulation so that the expansion of gas pockets within the dough during fermentation is retained. The gluten proteins stretch and become elastic through chemical interactions, and through the breakdown of proteins into amino acids, cross-linking gets promoted by the starter culture. The optimum rising temperature for bread during its bulk fermentation is only 80˚F: yeast multiply more rapidly at 95˚F, but they secrete by-products that deteriorate the quality of the bread. Yeast cells will die when the internal temperature reaches 140˚F, a crucial part of baking the bread because the yeast activity needs to be hyper stimulated during the initial baking time. When in a moist environment (i.e a steam oven), the yeast produces a ton of carbon dioxide, which causes the dough to inflate rapidly, per the term oven spring. If the bread over proofs or does not have enough tensile strength, the gas escapes and you end up with flat bread. If I included every single kind of bread in this blog, I'd be here forever. I'm not going to even attempt to make a general list, because each culture that predominantly grows grain or wheat for its staple crop has its own way of making grains more bioavailable. However, this is the first post in which I am including my recipe for what you can do with fermented foods! Obviously you can eat bread hot out of the oven, and it's delicious, but I wanted to make a tartine, a savory toast that relies on day-old bread. I topped it with roasted leeks and king oyster mushrooms, crispy fried Jerusalem Artichoke chips, and a yogurt espuma with harissa and preserved lemon (another fermented product I will make a post on later) that I produced using an iSi whip carbonator. Tartine of Roasted Leeks and King Oyster Mushroom, Crispy Jerusalem Artichoke, Harrissa + Preserved Lemon Yogurt EspumaIngredients:
Roasted Leeks and King Oyster Mushrooms: - 1 tbsp olive oil - smoked salt + black pepper, freshly ground - 4 leeks, washed and scrubbed, white parts only cut in half lengthwise - 3 king oyster mushrooms, halved and scored on the cut face Harissa and Preserved Lemon Yogurt Foam (Espuma): - 1 cup full fat plain yogurt - 2 tbsp homemade harissa paste - 1 tsp yuzu juice - 1-2 egg yolks, depending on how thick you want the emulsion - 1/2 tsp baharat spice mix - 1 tbsp lemon juice - 1 tsp preserved lemon brine - 1/2 tbsp pomegranate molasses - a few cracks of timut pepper Jerusalem Artichoke Chips: - 1 lb. Jerusalem artichokes, rinsed + mandolined, then soaked in cold salted water - 1 cup frying/vegetable oil - Chicken boullion powder - Smoked salt - Shichimi Togarashi For plating: - 2 slices sourdough or whatever kind of good fermented bread, toasted - Micro arugula Method: 1. For the espuma: combine all of the ingredients, and pour into the iSi whip. Charge with 1 canister, and place in the fridge to firm up for at least 30 min. 2. Meanwhile, preheat oven to 400˚F roast setting, and set up your frying station. Baste leeks and king oyster mushrooms with the oil, then place on a lined baking sheet and season with salt and pepper. 3. Roast for 15 minutes, then turn down the oven temperature to 350 and roast for another 15 minutes. 4. Meanwhile, pat dry the Jerusalem artichoke slices, and preheat your oil to 350˚F(a convenient way of telling if your oil is ready without the use of a thermometer is to start the oil cold with a scallion white; when the white is golden brown and the oil bubbles vigorously around it, you are ready to fry). Fry for about 7-8 minutes, or until golden brown and crispy. Remove from the oil and immediately season with the boullion, shichimi and salt. 5. To assemble: place a layer of the leeks roasted side up on the bread, then arrange the mushrooms on top depending on their size. Use the iSi whip to pipe a few mounds of espuma on top, then layer some of the chips on top. Decorate with the micro arugula and serve. Many of us eat yogurt for breakfast everyday; at my school, there's usually a tub of Chobani sweetened greek yogurt cups or some form of the thick, industrially produced version. However, the yogurt we know today bears some distinct differences to traditional yogurt, and fermented milk products. Yogurt is a byproduct of the Turkish name for fermented milk, and it originates from Southeastern Europe, specifically from the Caucasus mountain region. It has been mentioned in Ayurvedic documents written in Sanskrit as early as 6000 BC, and has existed for millennia as a means of preserving raw milk. At a time where pasteurization and homogenization of milk had not been discovered, there were limited ways of preserving milk, so people turned to drying or fermenting it in order to extend its shelf life. As such, every culture that produces dairy also has some product of fermented milk. The process of making yogurt usually relies on raw milk, because it contains a greater diversity of cultures. They are usually thermophilic bacteria, which are active at elevated temperatures between 110 and 115 degrees Fahrenheit, and the two most prevalent strains are L. acidophilus and L. bacillus. They are the only two strains required by law to be added to commercial yogurt, but many others such as Bifidobacterium bifidum or Lactobacillus casei are added due to their health benefits. Sandor Katz says in his book The Art of Fermentation that “According to geneticists Joel Schroeter and Todd Klaenhammer, humans “essentially domesticated these organisms over the last 5000 years through repeated transfer of LAB cultures for production of fermented dairy products”. Similar to many other fermented products, the drop in pH of the environment protects the milk from unwanted pathogens, which is achieved through the metabolic activity of LAB, which ferments lactose, broken down into glucose and galactose into lactic acid. The flavor of yogurt comes from this fermentation, which adds sourness, but according to a UCLA article on yogurt fermentation, “A mixture of various carbonyl compounds like acetone, diacetyl and acetaldehyde are also major contributors to the tarty yogurt flavor”. Making yogurt requires a starter culture, which contains the diverse series of bacteria that act upon the milk. The mix is then heated until it reaches a temperature of around 180 degrees, which allows the yogurt to thicken, due to the denaturation of certain proteins. It allows the proteins to form a gel and eliminates potential competitors, as yogurt is fermented until a pH of 5 has been achieved. This is the point at which the casein micelles lose their tertiary structure and the denatured proteins interact with other kinds, creating a semisolid structure and contributing to the final viscosity. After it is heated, the cultures are added, the milk is cooled until set and then fermented for anywhere from two days to upwards of a week. The rate of cooling and the initial temperature of the milk affect the final flavor of the yogurt, depending on the increased enzymatic and metabolic activity at higher temperatures. If the yogurt is cooled faster, it tends to be sweeter, whereas if it is left at room temperature, it can develop more acidic notes. Yogurt has been used in medicinal ways for thousands of years, but in the west, Ilya Metchnikoff, the pioneer microbiologist who studied longevity in Bulgaria gained notoriety when she attributed health to yogurt. This movement later spurred Dr Isaac Carasso to build a yogurt factory in Barcelona in 1919, which became known as Danone and then later changed to Dannon when he moved to America, creating the first industrial yogurt company. The yogurt Carasso made used a blend of bacteria isolated from Bulgarian yogurt, such as Lactobacillus delbrueckii (a subspecies of bulgaricus), and Streptococcus salivarius (subspecies of thermophilus), both of which have become commercial standards for the starter culture. However, this yogurt is not as strong in its resistance to unwanted microbes, as the diversity of yogurt cultures improves their stability. According to microbiologist Jessica Lee, with a single strain of bacteria, “a phage outbreak can quickly kill the entire bacterial population and end the fermentation process”, and even two isolated strains are vulnerable, as “eventually local bacteriophages evolve to be able to infect the few strains that make up that starter and slowly kill them off”. However, with multiple varieties of organisms present within the culture, if bacteriophages kill one strain, others can take over and protect the yogurt from spoilage. Thus, many yogurts are made using the "backslopping" method, where some of the original culture is added to the mix in order to jumpstart the selective environment that successful fermentation relies upon. There are many kinds of yogurt-like products in the world, but I will not be discussing kefir in this post. This is due to the fact that kefir is a little different, as it relies on a SCOBY (symbiotic colony of bacteria and yeast) that has evolved to create its own stable niche. According to Sandor Katz, kefir is a “symbiotic entity that self-reproduces; [and]combining each of the individual bacteria and fungal members will not result in a new kefir grain”. Since it involves a community of 30+ microbes that reproduce together via coordinated cytokinesis, and are connected by a series of biological molecules, the SCOBY requires another separate post to understand its complexity. Some of the yogurt products around the world are:
Yogurt is a perfect example of the diversity of global fermentation practices, as so many cultures rely upon milk as a dietary staple. It can be served thick, thin, sweet or savory, and it is gaining popularity in the culinary world as a way to thicken and add fat or flavor without as many calories as cream. The possibilities are endless: yogurt sorbet is becoming common, yogurt sauce is a staple in many cuisines, and dried yogurt (kashkh) is even added to some stews to enhance the fermented flavor. If you have the opportunity, try to look for real yogurt made from raw milk; try it once, and it might change your view on yogurt as a regular, sometimes boring breakfast option.
Ah, chocolate: almost everyone loves it, and it's going extinct rapidly (time to stockpile :)). However, you might not realize how much work goes into the bar that you eat, and that the quality of the chocolate has a lot more to do with fermentation than you think. Going from cacao to cocoa can take up to a month, and it all starts with the fruit shown below, which through the process of microbial degradation creates the flavors we love in our chocolate, bitter, slightly acidic, sometimes spicy, and aromatic. This fruit, when mature contains mainly glucose and fructose, stored in the disaccharide form of sucrose. The beans are inside the white pulp, which has a low pH (3-4) and is high in sugar, because of the presence of pectin, saccharides, and citric acid, which later act as metabolites for micro-organisms. Well, why ferment chocolate in the first place, you might ask? The fermentation of the fruit has several purposes:
We all love chocolate, right? (Well, at least I hope you do; if not, I don't know if I can be friends with you). But how does it get its flavor? As it turns out, producing chocolate starts with the cacao beans, which are originally in the form of a fleshy, sweet fruit. It is still a so-called spontaneous curing process, in which microbes from the air inhibit the beans and transform their flavor. At the first stage of fermentation, yeasts dominate the cocoa environment, with their depectinizing activity that transforms the pulp into a liquid from a gel form. Hanseniaspora opuntiae/uvarum is often present at the beginning, due to its low ethanol and heat tolerance, but it is later replaced by saccharomyces cerevisiae, which thrives in that environment. The initial yeast fermentation reduces the pulp viscosity and allows for air to get into the fermenting mass, which encourages the aerobic-respirating bacteria to develop. The most important job of these yeasts is to produce ethanol from carbohydrates, i.e alcohol fermentation, namely sucrose. This disaccharide is then converted through invertase hydrolysis mechanisms in the yeast metabolism into glucose and fructose, the latter of which isn’t broken down by yeast. The ethanol produced will partly diffuse into the cocoa bean cotyledons (the embryonic leaf of seed-bearing plants) and either be oxidized into acetic acid , consumed by aerobic yeasts or disappear through sweating or evaporation. This all is an exothermic process, and it raises the temperature of the cocoa mass to 35–40°C within 48 hours. Yeasts are critical to the final flavor of the chocolate, as they create some of the acidity in the final bar, while developing volatile compounds that determine how a bar tastes. These organisms also produce acid, which acts as a buffer against bacterial contamination. After 24-72 hours, the air in the fermentation pulp allows for the growth of aerobic enterobacteria, namely LAB (lactic acid bacteria) and AAB (acetic acid bacteria). Ironically, some papers have found that LAB isn't necessary for the development of chocolate flavors. Nevertheless, it is a crucial step in the fermentation process, as LAB controls bacterial growth, encouraging fermentation through the control of the environment and acidity level. Glucose that is still available after yeast growth is fermented into lactic acid, acetic acid, carbon dioxide and/or ethanol, similarly to fructose. Although LAB is most active at this stage, since temperature, acidity and ethanol concentrations increase later on, LAB eventually declines in population size. The third and final stage is aerobic fermentation, where acetobacter species oxidize the ethanol produced by the yeasts into acetic acid, and the lactic acid produced by the LAB into acetic acid and acetoin. Sometimes, mannitol is also formed, as shown by Figure 1, but it depends on the type of acetobacter and yeasts initially present, and the type of bean. As these bacteria also cause an exothermic reaction, the mass's temperature increases to 45–50°C and even higher, limiting micro-organism growth and killing off the cacao and the yeast. As the acetic acid concentration increases and the cotyledon pH lowers (from 6·3–7·0 to 4.0–5·5), internal membranes of the bean cotyledon compartments degrade, so that substrates and enzymes mix. This is a key step in the fermentation of the bean, as it allows the seed germ to die due to the low pH (see Figure 2), and for all of the proteins and phytonutrients within the bean to break down into their constituents. Important flavor precursors are produced through this bioconversion, such as reducing sugars, hydrophilic peptides and hydrophobic amino acids, which later encourages the Maillard reaction during conching (roasting). Many companies now use starter cultures designed to inoculate cocoa communities, as it jumpstarts the fermentation process for bulk quantities. Valhrona, the high-end French chocolate company, has even invented a new fermentation technique that sets their chocolate apart: they add the pulp of local fruits to the fermented cocoa mash. According to their website, “the natural yeast and sugars of the fruit pulp work just like the sugars from the natural cocoa pulp in the first fermentation, and kick off the alcohol and acetic fermentation once again.”
Cacao originally belongs to the Mesoamerican continent, and it formed an integral part of Pre-colombian society. It was offered as a form of currency, worship, and trade; used for religious sacrifice, medicine, and often it was consumed unsweetened, in the form of a drink called Cacahuatl in Nahuatl, the ancient language of the Aztecs. Atole was/is another popular drink, made from corn, cacao, sometimes a little piloncillo (Mexican brown sugar), vanilla and canela (cinnamon). However, when the Spanish conquistadores came in 1519, chocolate transformed into a sweetened good and a major form of commerce for the European society, combined with the sugarcane trade from slaves and indentured servants in the Caribbean. Although the Spaniards managed to keep chocolate secret for a hundred years, it was eventually introduced to the French when the daughter of Spanish King Philip III wed King Louis XIII in 1615. Chocolates thus began to show up prominently in European pastries and confectionary shops, and were prized for their exclusivity. Europeans thus began to colonize cacao-producing areas and install plantations, as a means of making a large profit. When diseases brought by the European explorers killed native Mesoamerican laborers, African slaves were imported to work on the plantations. Chocolate was originally reserved for the aristocratic, however, as it was so expensive; it became accessible to everyone in 1828, when Dutch chemist Coenraad Johannes van Houten invented the cocoa press. The machine could extract cocoa butter from the roasted cacao beans, leaving behind a dry mass that could be pulverized into a fine powder to mix with other liquids and ingredients, poured into molds and solidified into what we know today as chocolate. This is proof that fermentation is essential to our lives: something many of us consume every day undergoes a rigorous process of decomposition and chemical transformation, under the guidance of a certain microbial community. Think about that the next time you take a bite: how far that bean has traveled to get from the fruit to your bar. Before I go into the specifics of certain ferments, I want to give a broader definition. Fermentation comes from the Latin food fervere, meaning “to boil”, and Noma in Copenhagen refers to it as “the transformation of food through enzymes produced by microorganisms, whether bacteria, yeasts, or mold”. It has been used as a method of preservation and flavor enhancement for thousands of years, starting in the Mesopotamic region and China, and chefs today are revolutionizing the variety of products that are subject to this process. According to Arielle Johnson, scholar of food science at MIT: “Microorganisms live in or on their food source, and biochemically transform it to extract energy, producing metabolites in the process. In general, a pool of larger molecular weight, and usually less flavor-active molecules - like starches and sugars - are transformed into a more diverse group of tastier, smaller molecules, such as amino acids, organic acids, esters, sugars, and aromatic compounds.” Fermentation relies on the control of the environment, specifically the salinity level, moisture content, pH (potentiation of hydrogen ions), and temperature, which affect the activity of the microorganisms. There are thousands of species that act upon substrates, but I will describe some of the most common ones below.
It's undeniable that fermentation carries health benefits: in many foods, new vitamins are introduced, like cyanocobalamin and pyridoxin (B12 and B6), as well as acetate (vitamin E). Furthermore, certain compounds like anti-nutrients that prevent absorption or raffinose, the compound in beans that causes gas and bloating are rendered inactive through the fermentation process, as microbes consume them as fuel. Although the link has not been proved for certain, there is some evidence in the scientific community that suggests that fermentation can improve the health of the gut microbiome, and improve the immune system's resiliency, which is currently under investigation.
Fermentation has become an intrinsic part of our lives, from cheese to chocolate to bread, and a new wave of this tradition has begun to influence how the restaurant world shapes its cuisine. At Noma, René Redzepi and David Zilber have built an entire fermentation chamber dedicated to researching various ingredients and microorganisms, which they incorporate into their menu. While fermenting at home doesn't have to be as complex as squid garum or black garlic miso, simple saeurkrauts or kimchi can easily be made (and nothing compares to a version you make yourself!). As this is a topic river, I aim to cover only some of the basics, but I will get more in depth with specific products in the future. |
AuthorFood is the universal language. Archives
May 2020
Categories |