Is Soy Vegan? (Soy, Tofu, Soy Milk, Miso, Etc.)


Is soy vegan?

Soy is one of the most versatile food products and can be used in a wide range of commercial applications. Soy and its derivatives are among the most common ingredients you’ll encounter when scanning food labels for vegan-friendliness.

Is it vegan? Yes, soy is vegan. Soybeans (Glycine max), aka soya beans, are a species of legume native to East Asia, that are widely cultivated for numerous uses.1 So, it’s 100% plant-based and thus 100% vegan.

Sometimes, it can be more complicated—i.e. palm oil is plant-derived, yet many vegans want to avoid the stuff. Unlike palm oil, soybeans aren’t mired in controversy over the environmental impacts of their cultivation.

Why Soy Is Considered Vegan

Soy Is a Plant Food

Soy and other beans as well as peas and lentils are important sources of fiber, complex carbs, protein, and iron for vegetarians and vegans.2

In fact, societies that are considered to be largely vegan subsist mostly on legumes and rice. So, soy is about as vegan as you can get.

Soybeans are especially important for vegans, because compared to other plant foods, they have relatively high protein content, and can be used to make a variety of animal food substitutes like textured veggie protein, meat analogs, tofu, a and soy milk.3

Environmental Impacts

Largescale cultivation of any crop will have some negative effects on the environment. Soy isn’t particularly problematic in this area.

Certain environmental groups such as Greenpeace and the World Wildlife Fund (WWF) have raised concerns regarding soybean cultivation—especially in Brazil—as it has destroyed vast areas of Amazon rainforest, and is leading to further deforestation.4-6

However, much of the soybean production driving deforestation is due to the global demand for meat, which requires huge areas of land to be cleared in order to grow feed crops for livestock. So, animal agriculture is the culprit here.

According to the World Bank, animal agriculture is estimated to be responsible for upwards of 91% of Amazon rainforest destruction.7-9

Soy In Vegan Food Products

Soy is used in a lot of food products that are considered to be vegan staples. You don’t have to consume soy as a vegan, but you’d be missing out on a ton of variety and nutrition in your diet.

Traditional uses of soybeans for unfermented food include soy milk and tofu. Fermented soy foods include the popular soy sauce, fermented bean paste (used in miso soup), tempeh, and nattō.

Fat-free soybean meal is a significant source of cheap protein for packaged meals. For example, soybean products, like textured vegetable protein (TVP), is an ingredient in many meats and dairy substitutes.10

Soy Milk

Soy milk is a milk-like beverage that’s not from a mammal, but rather it’s made from soybeans that’ve been soaked, ground, and strained. So, it’s perfectly suitable for vegans. The stuff has been used for centuries in China and Japan and is thought to have been around since 150 BC.11

This is one of the most common forms of soy in the vegan diet. Imitation milk looks a lot like milk but lacks dairy.

Ingredients often include:

  • Water
  • A lactose replacement like corn syrup solids or sugar
  • Vegetable oils (to replace the milk fat)
  • Soy protein (to replace whey and sodium caseinate)
  • Stabilizers, and emulsifiers
  • Flavoring agents

So-called plant “milks” are not actually true milk, but they’re usually fortified with nutrients so they make great milk replacements. Not to mention, they lack the high saturated fat content present in most cow’s milk.

Soymilk is also used to make tofu, a soy milk “cheese” if you will. More on that below.

Infant formulas often use soy, but it is lacking in certain nutrients unless fortified. Infant formulas usually throw in the essential amino acid (EAA) methionine, vitamin B12, and calcium.38

Soy Protein

Most plant protein, with the exception of that found in soybeans and certain grains (e.g. amaranth and quinoa), is considered incomplete and will support the maintenance of body tissues, but not growth.

So, soy is an important source of protein for vegans, as it’s about as complete a protein source as you’re going to find in the plant kingdom. If one wanted to avoid soy protein, incomplete plant-based proteins can be used via a strategy known as protein complementation.

For more on that, check out the article on the best vegan sources of protein.

Soy Flour

Soy flour is a common ingredient in baked products and is often used in yeast breads. It’s higher in protein compared to other flours because it’s sourced from the soybean, which is actually a legume.

It has a higher content of the amino acid lysine compared to wheat, so it’s great for improving the nutritional profile of vegan-friendly foods, as vegans often lack the amino acid lysine.12,13

While, in principle, soy flour would be great for vegans who are gluten sensitive, as the flour has a much lower gluten capacity, the lower gluten content usually requires it to be combined with wheat in baked bread—the food product you’ll most likely encounter soy flour in.

In that vein, soy flour can only constitute up to 3% of the flour used in commercial white bread, for the product to be marketed as “white bread.”

This is despite the fact that you can get away with adding up to 20% soy flour and have the food product still result in essentially the same texture and color of whole-wheat bread.14

Soy flours are often added to bakery products at levels of around 3-6% of the total formulation.

Soy Sauce

A lot of savory condiments like Worcestershire sauce are unsuitable for vegans due to the presence of various animal products—like anchovy paste in the case of Worcestershire.

Fortunately for vegans, soy sauce is an animal-free condiment that has much of the same applications as similar non-vegan sauces. It tends to contain just four basic ingredients: soy, wheat, salt and water.15

Other potential ingredients include hydrolized vegetable protein, caramel color, and corn syrup.

Mock Meats

There are lots of non-meat substitutes on the market these days that provide an inexpensive protein source. They include dried beans (soybeans and their derivative tofu), lentils, and peas.

These legumes are packed with complex carbohydrates and fiber, and are among the highest-quality source of plant protein.16

Textured vegetable protein (TVP) is a term for protein derived principally from soybeans, though other plants like peanuts and cottonseeds can also be used. In TVP, the raw plant material is processed into porous, fibrous, granules that rapidly rehydrate when exposed to water.

Commercial TVP is available in both flavored and unflavored forms, as well as in natural and caramel-color.

Mock meats or meat analogs are imitations of meat, that are getting increasingly realistic these days with the Beyond and Impossible burgers. They’re made by blending plant proteins, fats, carbohydrates, vitamins, minerals, flavors, and colorings.

Nowadays, there are meat analogs in the form of breakfast sausages, ham slices, bacon, beef chunks, and chicken.

There are numerous hamburgers and hot dogs for sale these days that are made solely with non-meat ingredients. They contain 1/3 the fat of their meat counterparts, and no cholesterol.17

They’re often low in methionine (as soy lacks the AA), but if you’re not a growing infant or child, that’s probably a good thing given the link between methionine intake and high circulating homocysteine levels.

They are highly processed and tend to be high in sodium, so you’ll want to only consume them in moderation.

Tofu

Tofu is the oldest non-dairy “cheese”. It’s one of many vegan-friendly cheeses along with those made from almond and rice milk. Nowadays, some vegan cheese makers are using cashews as they’re also fairly high in protein (for plant standards) and contain a good bit of natural oil.

Some non-dairy cheeses (made for those with allergies) do, in fact, contain some milk and/or cream derivatives, so not all non-dairy cheeses are entirely vegan-friendly.  But, tofu in itself is always vegan.

Tofu is a cheese-like substance made from soy milk. The protein in soy milk coagulates like the casein in milk protein, precipitating out with the help of calcium sulfate dihydrate (for volume), calcium chloride (for calcium and firmness), or magnesium chloride.

After the soy precipitates out of the solution, the liquid is removed, and the resulting curds are pressed and shaped into fresh blocks of tofu.

So, if you ever wanted to try tofu, you can be sure that it’s perfectly suitable for vegan consumption.

Fermented Soy Products

Here we’ll touch on a few of the fermented forms of soy that are often inquired about in terms of their vegan status.

Soybean fermentation results in a variety of tasty foods, including natto, miso, sufu, tamari, and tempeh.

  • Natto. This is a traditional Japanese food made from cooked fermented soybeans held together by a sticky vitamin K2-producing bacterial product. It’s a rare source of plant-based K2. To learn more about that you can check out the article on vitamin K here.
  • Miso. This is a paste made from fermented soybean, that’s used as a seasoning for various food products like dressings, dips, sauces, and gravies, and most notably soups and stews (see miso soup below).29
  • Sufu. Sufu aka bean cake is fermented soybean curd. This fermented tofu product is marked by its cohesiveness and sesame oil-like consistency.30
  • Tempeh. This is a common meat alternative made from fermented whole soybeans shaped into a flat cake-like shape. It’s often fried up and put on sandwiches.
  • Tamari. Tamari is a form of soy sauce that’s naturally fermented over time. The ingredients are the same as standard soy sauce minus the wheat. Contrast that with a synthetic non-brewed soy sauce with soy protein, corn syrup, and caramel color.31 There are other types of soy sauce that are aged/fermented but do contain wheat. But, this version is one of the most common, so I’m listing it here.

Anyway, all of the above products are perfectly suitable for vegans.

Is Miso Soup Vegan?

Miso is a thin soup which is a type of soup that has a consistency somewhere between a thickened soup and a clear liquid soup.

Such soups are broth-based, so they’re not always vegan—it just depends on the broth.

Two common non-vegan soup stocks for miso soup include one made of niboshi (dried baby sardines) and one made from skipjack tuna.

Plant-based broths include Hoshi-shiitake (dried shiitake) and kombu (dried kelp). The kelp and shiitake dashi are popular among vegetarians.32 So, miso soups with these broths tend to be vegan.

There are other non-vegan ingredients you’ll have to look out for.  One of the more common forms contains a garnish of vegetables, starches, and cooked meats.

Popular vegan ingredients include seaweed, tofu blocks, and green onions.

There are numerous variations of the soup, and the common feature is, of course, miso paste. You’ll just have to vet the other ingredients.

Miso (the paste) is prepared by mixing cooked beans (usually soy) with salt and cultured barley (koji) or rice.

The mixture is then fermented anywhere from a few weeks up to 3 years, depending on the specific variant of the soup.33

Soy-Derived Ingredients and Food Additives

Soy Lecithin

Lecithin is a compound that makes the mixing of ingredients much easier as it prevents separation by attracting both fat and water molecules.

Soy lecithin is used in food products to keep mixed products stable, control crystallization, reduce stickiness, help ingredients dissolve, and help keep ingredients nice and dispersed.

You’ll run into this ingredient a lot in food products like salad dressings, chocolates, peanut butter, margarine, and frozen desserts.

Soy lecithin is perfectly vegan unlike other animal-derived and potentially-animal-derived emulsifiers like mono- and diglycerides, egg yolks, and sorbitan monostearate.18

Mono- and diglycerides are the most common emulsifiers in the food industry and are added to foods to improve emulsion stability, dough strength, texture, volume, and improve the tolerance of ingredients to processing.19

So, while mono- and diglycerides can be vegan-friendly depending on the source, soy lecithin is never animal-derived, and thus always suitable for vegans.

Soybean Oil

Vegetable oils are any oils derived from seeds, nuts, and fruits.20

The most common vegetable oils in food preparation include soybean oil, as well as canola, sunflower, cottonseed, corn, and safflower seed oils. But, in the US, soybean oil is synonymous with and marketed as “vegetable oil.”

Due to its lecithin content, soybean oil tends to be found in emulsions like salad dressings, etc.

Soybean oil is also used in shortenings and margarines. It’s the major source of oil used in hydrogenated vegetable shortenings. Think Crisco, etc.

It is hydrogenated to reach a solid consistency and then pumped or whipped with air to increase its plasticity which gives vegetable shortening a white color.

Anyway, a lot of folks ask if soybean oil is vegan, so you can be rest assured it’s perfectly suitable for vegan consumption.

Oligosaccharides

Oligosaccharide is a fancy term for a short chain of carbohydrates that’s longer than simple sugars like sucrose, but shorter than the really long polysaccharides.

The word “oligo” means “few” in Greek, so the term is used to classify compounds made up of three to 10 monosaccharides (glucose, etc.).

Two of the most common oligosaccharides are raffinose and stachyose, having three and four monosaccharides linked together, respectively. These saccharides are found abundantly in dried beans. They are not well digested by our GI tracts, but our intestinal bacteria love to gobble them up, which accounts for the undesirable formation of gas after consuming high FODMAP foods.

Anyway, they have several uses in food production. There are twelve categories of food-grade oligosaccharides used in commercial production and all are derived from soybeans, or synthesized directly.21

So, if you’ve ever seen “oligosaccharides” on food labels, you can be sure they’re 100% vegan.

Phospholipids

In the body, phospholipids serve a very important role as components of our cell membranes, where they help move hormones and fat-soluble vitamins in and out of cells. Animal products contain phospholipids for this reason. Liver and egg yolk have fairly high phospholipid content.

But, a lot of plant foods also constitute good sources of phospholipids, and soybeans are a good source. Wheat germ and peanuts are two more examples.22

Anyway, soy is a common source of industrially produced phospholipids, and you’ll no doubt encounter the ingredient on food labels when scanning products for vegan friendliness.

When you do, you can rest assured that phospholipids from soy are perfectly vegan-friendly.

Plant Sterols

Plant sterols have made the rounds in the media in recent years for the protective effects they’re thought to confer in promoting cardiovascular health.

Not all sterols are vegan. When derived from animals, they’re referred to as zoosterols, and when plant-derived, they’re called plant sterols.

Soybeans are great sources of plant sterols, so this is one soy derivative you’ll find in certain vegan-friendly products like margarine.

Soy isn’t the only plant that contains sterols. The compounds can also be derived from certain fruits, veggies, nuts, and seeds, as well as, other legumes, and cereal grains.23

But, plant sterols for use in fortifying margarines, etc. are often derived from soy. So, this is yet another soy derivative found in vegan food products.

Flavor Enhancers

There are a number of flavor-enhancing agents used by the food industry.

Substances like monosodium glutamate (MSG) and hydrolyzed soy protein enhance flavors already present in foods further improving the sensory experience and consumer acceptance of food products.

Other examples include disodium guanylate, disodium inosinate, and autolyzed yeast extract.24

Hydrolized soy protein is a common ingredient used in savory foods to enhance the umami flavor of mock meat products. So, it’s a common additive in vegan meat substitutes.

Gelling Agents

Proteins from both plant and animal sources are used in a variety of gels, and soy is a common source of proteins for gelling agents.25,26

Some proteins, like the those present in soy, are especially good at forming gels when exposed to water, which allows them to be used as binders, thickeners, and stabilizers, in a range of food products like confectionaries, preserves, and desserts like vegan ice cream, custards, puddings, mousses, and pie fillings.27,28

Non-dairy ice cream is a common vegan food you’ll find plant proteins like soy.

Soy In Non-Vegan Food Products

Just because a product is plant-based doesn’t mean that every application of the product will be in vegan-friendly food items.

Meat

Due to the growing awareness the link between saturated fat, empty calories, and heart disease, manufacturers sought to increase consumer acceptance of meat products by lowering fat content without sacrificing taste and quality any more than possible

They found that the fat in ground beef could be reduced by replacing some of the animal flesh with low-calorie extenders like texturized vegetable protein (TVP), fat-free dry milk solids, plant soy proteins, starches, fiber, oats, maltodextrin, modified food starches, and vegetable gums (e.g. carrageenan).34

Obviously, the quality and taste still suffered, but adding the extenders went a long way to help maintain the texture.

Soy is used in a lot of restructured or fabricated meat products like hotdogs. These products are made from the meat trimmings or leftover meat from lower-grade carcasses. The meat is mechanically separated into particles and then bound together again in various uniform shapes and sizes.

Soy protein is a natural binder that’s used between the meat’s proteins. Other binders include used for this purpose include egg albumen, gelatin, wheat and/or milk proteins.35

Soy-based TVP is commonly added to extend ground meats to lower fat content and reduce costs.36

As of now, the USDA limits the use of TVP and soy in commercially prepared meat products to no more than 30% of a given product.37

Now you know why restaurant chains advertise 100% beef. One would think it would be obvious that a hamburger would be 100% beef, but that’s not the case with fast food joints. They brag when it’s 100% beef because fast food patties are notorious for being high in soy protein.

Anyway, this is one non-vegan application in which soy is used.

Conclusion

Thanks for reading. Hopefully, that gives you a good idea of the various forms of soy in food and their vegan status.

For similar reading, you may want to check out the following articles:

References

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  4. Fargione, Joseph; Hill, Jason; Tilman, David; Polasky, Stephen; Hawthorne, Peter (February 2008). “Land Clearing and the Biofuel Carbon Debt”. Science. 319 (5867): 1235–38.
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Drew Davis

Hi! I'm Drew and this is the place where I nerd out about vegan and plant-based diets. I have a BS in Nutrition and Dietetics from the University of Alabama and have taken dozens of classes in areas like organic and biochemistry, food science, medical nutrition therapy, nutritional genomics, and vegetarian diets. I'm still learning every day, and on this blog, I'll be sharing everything I discover about vegan diets as I go.

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