Soy sauce, a common condiment throughout Asia, is a fermented sauce with a salty taste which is aged for several months. Kikkoman says its soy sauce consists of five flavors: sweet, sour, salty, bitter and umami -- a flavor created when soybean and wheat, two ingredients in the sauce, are broken down into different proteins. The website claims their soy sauce contains only four ingredients: soybeans, wheat, salt and water. A fifth ingredient, aspergillis, a type of fungus, is added to produce Koji mold, which activates the fermentation that creates the soy sauce.
Soy sauce contains only 10 calories per tbsp. According to LIVESTRONG.com MyPlate, 2 g come from protein. Since protein contains 4 calories per g, a 1 tbsp. serving supplies eight calories from protein, most of which comes from the soybean. This equals 4 percent of your daily protein requirement based on a 2,000-calorie-per-day intake. Carbohydrate and fat amounts are listed as zero, the sauce could only contain minute amounts of both.
Soybeans are legumes that contain isoflavones -- substances that have effects similar to estrogen, the dominant female hormone. Soybeans are also good sources of protein. When eaten in larger quantities as part of a meal, soybeans may help lower cholesterol levels. However, the number of soybeans used to make a single serving of soy sauce is small.
Soy sauce contains a small amount of wheat, which is roasted and then crushed to help the fermentation process. People who are allergic to wheat or who have a gluten intolerance should avoid soy sauce. Kikkoman recently began producing a soy sauce for those allergic to wheat. It is made with rice.
Kikkoman soy sauce contains a large amount of sodium per serving -- 920 mg, or 38 percent your maximum daily sodium intake of 2,400 mg. The Mayo Clinic suggests keeping sodium intake to 1,500 mg, especially if you have high blood pressure, kidney disease or diabetes. Sodium can increase blood pressure, which can damage blood vessels and increase the risk of developing heart disease. The Mayo Clinic recommends avoiding any foods that contain more than 200 mg of sodium per serving. Because the sodium count of soy sauce is so high, use it sparingly and occasionally rather than as a regular condiment, and don't use it at all if you have any risk factors.