Beneficial Uses of Bacteria

SOY SAUCE

Soy sauce, Shoyu, in Japanese, is a liquid seasoning that is currently used in cooking worldwide. The varieties of soy sauce that are produced depend on the various types and ratios of raw materials used, the microorganisms employed and the conditions of fermentation. Soy sauce was first made according to legend , by Buddhist bishop, Kakashin, at Yuasa, Wakayama, Japan, in 1254 . Traditional soy sauce is produced in wooden tanks by static fermentation for 1-2 years. In China, about 5,000 years ago, people grew soybean crops for food and animal feed. Because soybeans spoil easily, salt was added as a preservative. Overtime the beans fermented much like pickles or sauerkraut. Unlike pickles, however, the soybeans turned into a paste called miso as they ferment. The paste is easier to digest than the unfermented soy beans, and people have been eating it for centuries. About 500 years ago, someone discovered that instead of discarding the sauce at the bottom of the barrels, they could use it for cooking. Thus, soy sauce was invented.

The making of soy sauce has always used microorganisms, traditionally by static fermentation, where the soy beans were added salt for preservation and let sit for a few days to some years, not to be mixed. Nowdays , soy sauce can be mass produced with the use of industrial machines and cookers. Soy sauce brewing is done in 3 stages. First, the soy beans are steamed and mixed with toasted crushed wheat. Fungi Asperagillus oryzae and Aspergillus sojae are added to the mixture to make kogi (the first step in the soy sauce-making process) that is then left uncovered for a couple of days. Next, salt and water are added to kogi to form a mash called moromi. Moromi is then put in an airtight container where it is allowed to ferment for at least 6 months. The mash is then squeezed to get the liquid soy sauce. Finally, the liquid is filtered, pastuerized, and tightly bottled for distribution.

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