I am going to talk a bit in this post about how soy sauce is made, some different kinds of soy sauce and how to choose a soy sauce. I also will include recipes for cherry tomatoes with soy sauce dressing and wonton soup with bok choy and soy sauce - since cherry tomatoes and bok choy are in your CSA boxes this week.
Not all soy sauce is alike
Like wine or olive oil, soy sauce is a complex substance. Soy sauce, a fermented food product, exists in a great variety of flavors, colors, consistency, saltiness and fragrance. These characteristics are due to differences in both ingredients and production methods. For example. some soy sauce has no wheat and some may be as much as half wheat. More wheat means more sweetness. Some is aged for three days (avoid this kind) and some is aged for six years. Some soy sauce is best suited to cooking and some to being used uncooked for dipping, sauces or marinades.
How is soy sauce made?
Traditionally, soybeans or soybean meal was mixed with roasted grain to form a mash. The mash is inoculated with a culture of special microbes. Salt and water is added and the mash placed in uncovered giant earthenware urns, where it would ferment in the sun. I am sure there is still artisanal soy sauce still being made this way somewhere.
Most modern soy sauce is made in industrial facilities, but using the same basic traditional fermentation process. It takes time and quality ingredients to make good soy sauce. Some say that making a fine soy sauce requires as much art and skill as making a fine wine.
Japanese soy sauce
Soy sauce is an all purpose seasoning in Japanese cuisine. Even bigger than ketchup or salsa in America. It is called shoyu and is made from soybeans, wheat or barley, salt and water (maybe malt). There are as many as five kinds of shoyu in Japan - they are not interchangeable. Over 80% of the soy sauce used and produced in Japan is "koikuchi" - it contains equal amounts of wheat and soy and is generally referred to as simply shoyu, since it is the most common. For an excellent discussion of the different types of Japanese shoyu - including tamari - see http://www.kikkoman.com/foodforum/thejapanesetable/25.shtml
Tamari is made with very little wheat (it can be found wheat free for those who are intolerant to gluten). This type of soy sauce, because of its small proportion of grain, is probably most similar to the original soy sauce introduced into Japan from China.
Chinese soy sauce
There are two basic types of Chinese soy sauce - light or "thin" soy (sang zul) or black or dark soy (low zul). The latter is darker, thicker, richer in color and slightly sweeter in taste. It is aged longer than thin soy and has some added molasses for sweetness. It is less salty than thin soy and is commonly used during cooking.
Light soy (also sometimes called "superior soy") is saltier, lighter in color and some say has the best flavor. It is from the first "pressing" of the soybeans.
Fake soy sauce
I was not surprised to learn that enterprising food scientists have figured out a way to use hydrolyzed vegetable protein, corn syrup and caramel coloring to come up with what I consider fake soy sauce. It only ages three days, is cheaper and has a longer shelf life. LaChoy is an example of this kind of soy sauce. I encourage you to consider a different brand that uses the traditional method of fermenting soybeans and grain.
What is the best kind of soy sauce to buy?
Cooking with soy sauce
Sometimes the soy sauce flavors "cook out" during cooking. I often add soy sauce near the end of the cooking process for that reason.
Cherry tomato salad with soy sauce
(from How to Cook Everything by Mark Bittman)
Dressing: 2 T soy sauce (plus more to taste); 2 t. dark sesame oil; pinch of sugar; 4 cups cherry tomatoes, cut in half; 1/2 cup whole basil leaves, preferably Thai basil; freshly ground pepper
Combine all in a bowl, stirring gently to coat tomatoes with dressing.
Let stand at room temperature at least 15 minutes before serving.
Wonton soup with bok choy and soy sauce
This straightforward recipe is from the Kikkoman web site. http://www.kikkomanusa.com/homecooks/recipes/recipedetail.php?rd=2018