I have a strong love hate relationship with soy. I think. OK, it's more of a love relationship, to be honest with you. I mean, soy is indeed a veg*n's best friend, right? Or is it? You can certainly find a lot of substantial evidence for both sides of the soy story. More on this later...
Kitchen Table Questions About Soy. I'm not going to simply regurgitate the conflicting data spread across thousands of published articles on soy. I prefer to start with what I know for certain: my food. The kind I eat. Whole food. So as I sit here plucking tiny tender green soy beans, known as edamame, from their never-been-opened by man green bean shells, I start my investigation with a few kitchen-table thoughts.
The Many Faces of Soy. Fact: My edamame soy beans are whole foods that were farmed, picked and piled into frozen bags to be shipped to Whole Foods Market where I bought them. Easy. But that white creamy soy milk inside my fridge and that oddly perfectly cubed block of tofu are a bit more mysterious to me. There is no tofu tree or soy milk plant. So I just ask: What is a soy bean? Where do my soy products come from? And why in the world are my soy beans green when my soy milk and tofu is white? Lets find out...
Is Soy Good for You? Yes! And no? Let's discuss. Soy contains a complete amino acid profile when it comes to vegetarian protein, and soy contains the nutrition-buzzword soy isoflavones, which may be beneficial in lowering your risk of everything from cancer to heart disease. But perhaps like me, you've heard a few rumors discussing the dark side of soy. A number of published studies have shown that too much soy may be a bad thing. So, who do we believe? Asian cultures have been eating high amounts of soy for centuries, and appear to be doing just fine. In fact, Japan continues to have a soaring life expectancy age of 82 years of age. Impressive. So as I said above, my investigation of soy will start at my kitchen table, rather than an article database.
Why are my Edamame Soy Beans Green? This is an easy answer: not all soybeans are green. Just as not all coconuts are brown and not all mushrooms are the size of a portobello mushroom. It all depends of when and why that food was harvested. It's age of maturity in the growing process. A good example to examine is a coconut...
Young vs. Old Coconuts. Those brown, small, hard and fuzzy coconuts are simply, old-mature. Inside they have a thick white flesh shell and a small amount of coconut water/milk gushing around inside. Grind the flesh and water together, and you get 'coconut milk'. Coconut milk is high in fat and a thick white color. However, take that same coconut at an earlier stage in its life and you would find it to be large, green, with a smooth shell and filled with only a thin amount of a creamy white flesh and a lot of gushing liquid (or endosperm) known as coconut water. Grind up this coconut water and flesh and you will get a different version of 'coconut milk'. Same coconut, different age, different insides. I even discussed this back when I found a mysterious white coconut a while back. The same basic theory of young vs. old, applies to my green edamame. Young soy beans are green, sweeter and used to make edamame. While a mature or aged soy bean will be beige to brown and will most likely used to make soy products such as tofu and soy milk. They may also be dried and sold as soy nuts.
What is Tofu? Tofu is coagulated soy milk. Simple as that. Green Options posted a great description of the process:
"To make tofu, we use soy milk. Now, most commercial tofu makers make their own soy milk, which anyone can do by soaking, grinding, boiling, and straining dried (or, less commonly, fresh) soybeans.
When you have your soy milk, you then need to add a coagulant. When you coagulate something, you cause it to curdle. In other words, you transform it from a liquid into a soft semisolid or solid mass. "
Tofu is made from White Soy Milk. So now that we have the tofu mystery solved (tofu is white because it is made from white soy milk). Why is soy milk white if my edamame is green? Well as I hinted, soy milk is usually made from mature and/or dried soy beans which are beige or brown in color. The processing of these beans leads to a milky white soy milk color. Thus, soy milk is white because it is commercially not made from young beans.
Which Bean is Better? So my next question is: what is the difference between young and old soy beans? I know that the nutrition properties of 'old' coconut milk vs. 'young' coconut water varies drastically. So why don't I ever hear the difference between mature soy milk beans and young soy bean edamame?
Lets investigate:
Google Searching for Image Answers. A image never lies, so maybe I could find some answers from the image search web. My quest: find out if green tofu or green soy milk exists! Oddly enough, when I googled "green tofu" for images, the first few images that came up were of a Green Tofu Salad that I posted a while back. It used white tofu and some edamame-not what I'm seeking. But a few pages down, I did find this interesting image of actual green tofu made from edamame beans. Green Tofu Link here.
Green Soy Milk? Next, I googled "green soy milk" and found one photo of an adventurous blogger who indeed made her own homemade soy milk using green colored soy beans. Note that these were not 'edamame' but rather black hulled soy beans that are green in color when the black shell is removed. Just as I imagined, the soy milk made from green colored beans came out a pale green color, rather than a milky white. Brilliant! Looks delicious! Green Bean Soy Milk Link here.
NOTE: Make your Own Soymilk? If you have ever attempted to made soy (or soya) milk from edamame beans please let me know! I've found a few text references to it online, but an actual blog post with recipe/images cannot be found. Anyone adventurous out there to try it with your soymilk machine???
What is Healthier? Green or White? So now that I've discovered that commercial tofu and soy milk is simply not made with green soy beans, thus is not green, my new question is: what is healthier? Edamame or mature soy beans?
Nutritionally Speaking. If edamame is healthier, then perhaps my soy milk, burgers and tofu should be coming from those yummy green beans instead of white/beige! And maybe I should be tossing whole edamame beans into my salad rather than chunks of white tofu.
The Facts:
If you compare young beans (edamame) to mature soy beans, there are indeed a few nutritional differences, although the basic components of fat/carbs/protein stay generally the same. Here are the biggest changes in nutrient profiles:
Nutrient facts for these serving sizes:
Edamame (⅓ cup).
Mature beans (a bit more than ⅓ cup due to water content changes)
Both servings contain 113 calories.
Potassium
Edamame (young/green): 14% RDA
Mature Soy Beans (white/beige): 10% RDA
Calcium
Edamame: 15% RDA
Mature Soy Beans: 7% RDA
Thiamin
Edamame: 22% RDA
Mature Soy Beans: 7% RDA
Selenium
Edamame: 2% RDA
Mature Soy Beans: 7% RDA
Vitamin C
Edamame: 37% RDA
Mature Soy Beans: 2% RDA
Iron
Edamame: 15% RDA
Mature Soy Beans: 19% RDA
Manganese
Edamame: 21% RDA
Mature Soy Beans: 27% RDA
Copper
Edamame: 5% RDA
Mature Soy Beans: 13% RDA
CONCLUSION: So I've answered a few fascinating questions regarding soy beans:
*Soy milk is white because it is processed commercially from white or beige 'mature' soy beans. If it were to be made from young edamame beans, it would indeed take on a more greenish color.
* Tofu is not green because it is made from soy milk. Green tofu is possible if you use a soy milk made form edamame.
*While the nutrient profiles for young vs. old soy beans vary slightly, it is not so drastic to turn you off of commercially processed soy products vs. edamame soy products that you could make at home with a soy milk machine.
*lastly, whole foods that are as close to their natural grown state as possible are always best. Processing will almost always affect the food in both appearance and nutritional value. So while processed soy products are good and well, whole soy beans (young and old) that have not been processed are the optimal way to consume soy.
Everything in moderation. And eat a mix of edamame/tofu/soy milk.
Anonymous says
"genetically modified soy can be found in about 60 percent of all processed foods, most often as oil or filler"
"Soy is one of the Amazon's leading causes of deforestation"
(Fordlandia by Greg Grandin page 366)
Anonymous says
Thank you so much for the extensive research and writing you had done on soy beans. I have had soy all my life and didn't know the difference between the young and old beans. Wow! was I educated just a few minutes ago. Again, thank you! 🙂
EdieS says
As a person who is vegetarian only six days a week ( I do eat meat with friends for Sunday Brunch) my concern is making sure I get whole sources from a variety of sources. It can be tempting to plan a meal around tofu or just soy milk- that's just doing a substitution for dairy imputs instead of working to incorporate other sources of plant protein into the diet.
Right now, my current obsession is with quinoa. It is an amazing psuedocereal, so easy to digest and a source of complete amino acids. This along with beans or vegetables is a great way to get protein with resorting hunk of tofu/hunk of meat thinking.
whatissuitetabu.com says
Really Great article! On my 3rd week of being Vegan.
Live Well,
http://www.whatissuitetabu.com
whatissuitetabu.blogspot.com
Kathy says
Lise,
Lots of great contributions in your comment. Thanks for that.
The discussion and learning should never end. You give some very good points.
However, I will say that if you compare the soy bean/tofu consumption of those in Japan vs. the USA there is historically a big gap. Mainstream USA has only just begun to truly embrace soy products in the past 30 years. Soymilk in coffee even 15 years ago was a very rare sight.
...perhaps as soy consumption rises in the USA, we will see an increase in thyroid issues. That is the frustrating part-we really don't know where the new age high soy diet will take us health wise. At least I don't. To me, it all ends in eating whole natural foods-a wide variety of them. A variety of veggie proteins such as nut, hemp, pea, wheat and soy are what I try to eat. Like I said, love/hate relationship with soy....
Again, great input-thanks
Kathy
Lise says
Actually, the 'Japanese live to 82 by eating tofu' is a bit of misinformation that's spread around and not really correct. There are a few studies looking at the diet and longevity of Okinawans, and the one that is examined and cited a lot was done in the '50s (I for one would like to see more recent data, but have not found any). Their diet consists mostly of sweet potatoes (~70%), a lot of local herbs & vegetables, fish, seaweed, and tofu (~6%, 2oz a day), so how tofu = long life was gotten out of that study is baffling (except possibly due to marketting by the soy industry) - especially when consumption of seaweed (=iodine) is so much higher than in American diets. (The Diet of the World’s Longest-Lived People and Its Potential Impact on Morbidity and Life Span Ann. N.Y. Acad. Sci. 1114: 434–455 (2007) for a recent review and discussion)
Historically, Asian cultures ate far more fermented soy products, like tempeh and soy sauce, than fresh, or else they would cook soy beans for a long time before using them, so the argument of "Asian cultures have been eating soy for ages" is doubly misleading. The reason that (currently) Asians are at a higher risk for thyroid problems underscores this fact - in that the culture, as a whole, has not lived with unprocessed soy beans for a very long time.
Trueandspurious: fermented (and boiled) soy products are broken down and many components, most of the isoflavones in this case, are not active, so they would not be inhibiting thyroid peroxidase (needed to make t3/t4 thyroid hormones) any longer. There are other issues with excessive soy consumption as well - just do a literature search (on PubMed or similar). There is a lot of positive blogging going on about soy, encouraging *too much* consumption, and it's worrisome to me (a biologist).
Kathy says
Dora, thanks for this comment. I will clarify this in my post!
Kathy
Dora says
Old coconuts don't have coconut milk inside them! They still have water, but with different nutritional value. Coconut water or cream is made by blending water with the mature coconut meat and staining it!
pigpigscorner says
Very informative. I didn't know Edamame is a type of Soy Beans and in fact, I always though soy beans are yellow. My mum used to make soy milk from those yellow beans.
Angela says
Thought I'd offer some insight on the thyroid question/concern.
http://www.thesoyfoodscouncil.com/pdf/thyroid.pdf
I'm happy to answer any more questions about this topic or connect you with a leading researcher in the field.
Kathy says
Thanks for all the great comments!
I'm so glad you all share my curiosity for these common 'kitchen table' questions. Scientific research certainly has its place, but with so much conflicting information out there regarding health/nutrition/diet/food, sometimes you don't have to look any further than your own kitchen table to find a good answer. All you have to do is go ask sturdy, answerable, common sense questions about your food.
~Kathy
Kathy says
Another green soy milk and tofu quip I found from the web:
"Just last month, I managed to catch this Japanese cooking show on JET TV, I do not know the name of the show, as my japanese is awful, but it was hosted by a fuunny chef with a mustache and he was walking around what looked like a part of Tokyo( wearing chef's whites and a chef's toque) with his co hosts, and trying different places .
He walked into what looked like a side walk restaurant run by a woman. The woman showed a bowl of green soybeans ( ?) from which she made green soymilk. She then added nigari, and placed the resulting tofu in a steamer.
After steaming she presented the green tofu and called it "Midori Tofu "
Link: http://forums.egullet.org/index.php?showtopic=42292&pid=633285&mode=threaded&show=&st=&
I wonder why more chefs and at-home soy milkers don't try green tofu and soy milk and blog about it! I may have to try this myself...
Kathy
Kathy says
Kecily,
Yes I should've clarified this better that the green soy beans used int he green soy milk were in fact black hulled beans. But my main purpose was to find out if any variety of green soy bean would turn into green soy milk. This post was a great example of how different varieties and colors of soy beans produce different colors and varieties of soy milk.
Kathy
Kecily says
Well, the link to the green soy milk you have in your post actually calls for unhulled black soy beans as shown in the picture and written in the text.
Kristen's Raw says
Wonderful post!
Cheers,
Kristen
Anonymous says
this is such a great write up about soy! very thought provoking!
Angela says
Thanks so much for taking time to explain the some of the different types of soybeans (there are black soybeans too!) and how some of the soyproducts are made. The Soyfoods Council is also happy to be a resource for anything soyfoods related: making soyfoods, cooking with all the different soyfoods and nutrition.
Thanks for always making such great-tasting, great-looking recipes with soyfoods!
Angela says
Great blog post on soybeans and soyfoods! A lot of people wonder how the different soy products are made. The Soyfoods Council is always happy to be a resource. http://www.thesoyfoodscouncil.com.
Thanks for helping spread the word about soy and making so many great-tasting (and looking) recipes with soy!
DJ Karma says
Fascinating! I was just wondering about what type of soy bean to use for making soy milk! Thanks for the answers... I'd love to try green soy milk 😀
Ana Banana says
Maybe I should pull out the soymilk maker. Does edamame soymilk taste differently. I know the soymilk I make at home tastes nuttier than the stuff you buy, but I've never done it with the green beans before.
Anonymous says
Ah, I've always wondered about that! My doctor does say though that you really don't want to eat too much soy. They live to be 82 in Japan, but they and other Asian cultures have a high risk of thyroid cancer and other thyroid problems from too much soy. She said to eat tempeh instead of tofu or soymilk. I know tempeh is fermented tofu (right?) but why it doesn't also cause thyroid problems, I don't know.