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:
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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. |
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May 2020
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