Two products share the name soy sauce, and only one of them was brewed

The Sunday Teardown · Pantry

There are two products in the soy sauce aisle, and they share a name. One is made from soybeans, wheat, salt and water. It sits in a tank for about 6 months while a mold, a yeast and a bacterium take the protein apart, and then it is pressed and heated. The other is made from soy protein and hydrochloric acid in a reactor. The acid is neutralized with lye, the liquid is colored with caramel and sweetened with corn syrup, and the whole job is finished in a day or two. Both say soy sauce on the front. Nothing in American law asks either of them to say anything else.

That is the issue this week, because the gap between those two bottles is wider than the gap between almost any two products that share a shelf label. A brewed soy sauce is a fermented food, in the same sense that wine, cheese and bread are, and the plant that makes it is a brewery with tanks the size of a house. A non-brewed soy sauce is a chemistry product, and the plant that makes it looks more like a flavor house. On the back label, the 3 words hydrolyzed soy protein separate them. The sodium number separates them again. That is all the help a shopper gets.

So this week I want to walk both plants. One is the brewery in Walworth, Wisconsin, whose owner sells more than half the soy sauce that goes into American homes. The other is the reactor that makes the cheapest bottles on the same shelf. Then I want to put a 10 ounce bottle of Kikkoman next to a 10 ounce bottle of La Choy and work out what the extra months bought. The answer has less to do with pennies than you'd expect and more to do with one chemical. I will get to it.

The Kikkoman bottle, the one with the red cap, lists water, soybeans, wheat and salt. That is the whole list. A tablespoon has 10 calories, 960 milligrams of sodium, which is 42% of a day, 1 gram of carbohydrate and 2 grams of protein. The label says brewed in the USA, which means Walworth, Wisconsin or Folsom, California. The La Choy bottle lists water, salt, hydrolyzed soy protein, corn syrup, dextrose, caramel color and potassium sorbate as a preservative. A tablespoon has 1,120 milligrams of sodium on the retail spec sheet, 1,460 on the foodservice gallon, and less than a gram of protein. The label calls it original soy sauce and gluten free. The word brewed does not appear on the bottle or anywhere on the brand's site. Neither does the word fermented. I would not expect either.

Soybeans and wheat. In a brewed sauce these go in whole, in about equal weights. The soybeans are steamed and the wheat is roasted and cracked. Between them they supply all of the protein, sugar, color and aroma in the bottle. The wheat is not filler. Its starch is what the yeast turns into alcohol and into the hundreds of aroma compounds that give Japanese style soy sauce its smell. It is also the reason a regular Kikkoman is not gluten free, while a tamari, made from soybeans only, is.

Hydrolyzed soy protein. This is the first ingredient after water and salt on the La Choy label, and the whole issue hangs on it. It is soy protein that has been boiled in hydrochloric acid until the long protein chains break into free amino acids, then neutralized and filtered. The federal rule on protein hydrolysates, 21 CFR 102.22, requires the label to name the plant the protein came from. That is why the words are hydrolyzed soy protein rather than the older hydrolyzed vegetable protein. The same ingredient turns up in soup bases and bouillon under the same name.

Salt. The second ingredient on La Choy, the fourth on Kikkoman, and in both bottles the one that sets the sodium number. In a brewed sauce the salt goes in as a brine of about 18 to 22% and comes out at about 17 to 18% in the finished sauce. The brine is there to keep everything but the organisms you want from growing during 6 months in a tank. In a non-brewed sauce some of the salt is added and some of it is made. Neutralizing hydrochloric acid with sodium hydroxide produces sodium chloride, so the reactor makes its own salt.

Corn syrup, dextrose and caramel color. A brewed sauce gets its sweetness from the wheat, its color from the browning reactions that run during months of aging and a final heating step, and its body from dissolved protein. A non-brewed sauce has none of that history, so each of those properties is added back as a line item. Corn syrup and dextrose supply the sweetness. Caramel color supplies the color. The hydrolysate itself supplies the savory depth that the brewery gets from the koji.

Potassium sorbate. This is La Choy's preservative. Kikkoman's retail bottle has none, although the foodservice jugs and bulk drums list sodium benzoate at less than 0.1%. The reason a brewed sauce ever needs a preservative is a salt tolerant yeast called Zygosaccharomyces rouxii. It is also one of the organisms that brews the sauce. It survives 25% salt, and in an opened bottle it will grow a film on the surface. In the plant, heat kills it. In an opened foodservice jug, benzoate stops it. The retail bottle relies on the heating step, the salt, the alcohol the label lists at more than 2% by volume, and the instruction to refrigerate after opening.

There is no federal standard of identity for soy sauce. FDA has standards for macaroni, mayonnaise, ketchup, canned peas and 20 odd other foods in Title 21. Soy sauce is not among them, so the name is a common or usual name with no recipe attached. The only US government document that separates the two products is Commercial Item Description A-A-20087D, the specification the Defense Logistics Agency uses when it buys soy sauce for the mess hall. It defines Type I, fermented, and Type II, non-fermented. It sets a minimum protein of 7.5% for the first and 4.5% for the second. It sets no labeling rule for either. The Pentagon writes the difference into its spec, and nothing requires the grocery shelf to.

Japan handles this differently. The Japanese Agricultural Standard for soy sauce defines 3 production methods. Honjozo is brewed from the mash and nothing else. The 2 blended methods add acid or enzyme hydrolysate before or after fermentation. Japan's food labeling standard requires the method to appear in parentheses after the product name, so a Japanese shopper can read whether a bottle was brewed. In 1998 Japan took that idea to Codex, the international food standards body, and asked for a world standard that would separate fermented from non-fermented soy sauce. The United States position was that labeling should be left to each country. In 2005 Codex recorded that there was no consensus and dropped the work. In the 20 years since, the only Codex document about soy sauce is a code of practice for keeping a contaminant out of the non-brewed kind. That contaminant is the subject of the second half.

What gets me is not La Choy. La Choy's label is accurate and complete, has been for decades, and the company makes no claim it can't back. What gets me is that the word on the front has been allowed to stand in for the words on the back. A product with 6 months in it and a product with a day in it meet the shopper as equals, and the only thing that separates them in the aisle is a 3 word ingredient and a sodium number nobody reads. If the country doesn't define the word and the agency doesn't define the word, what does soy sauce on the front of the bottle mean?

Below the line for paid subscribers. I walk the brewery in Walworth from the koji room to the press, then the reactor that makes the non-brewed kind, including the chemical the acid produces and the two very different limits Europe and the FDA put on it. Then both bottles get priced line by line, which does not come out the way most people assume. I close with the tamari question, the sodium target FDA set for the category, and what I buy.

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