What is soy yogurt?Soy yogurt is made by fermenting soymilk with friendly bacteria, mainly Lactobacillus bulgaricus and Streptococcus thermophilus. The process is similar to the production of yogurt from cow milk. Yogurt production was invented probably by accident by Balkan tribes thousands of years ago. Yogurt remained mainly a food of Eastern Europe until the 1900s, when the biologist Mechnikov theorized that lactobacillus bacteria in yogurt are responsible for the unusually long lifespan of the Bulgar people. Mechnikov then popularized yogurt as a foodstuff throughout Europe.
The sugars are fermented by the bacteria into lactic acid, which causes the formation of the characteristic curd. The acid lowers to pH of the yogurt to about 4.0 and restricts the growth of food poisoning bacteria. The bacteria produce lactase which breaks down the lactose in dairy milk. Soy milk does not contain lactose but other sugars such as stachyose and raffinose.
It is difficult to find soy yogurt in supermarkets but you may find it health food shop. Or you can make soy yogurt at home. You can use store-bought yogurt as starter or even Solgar capsules that contain Lactobacillus bulgaricus and Streptococcus thermophilus. In some countries, soy yogurt is labelled as "cultured soy milk" because the term "yogurt" is reserved for dairy yogurt.