A traditional yogurt is made by the action of specific bacteria on cow's milk. Soy milk yogurt has soy milk as an ingredient instead of cow's milk. Soy milk is not an animal product but is made from the beans from the soy plant. Therefore, soy milk yogurt is an alternative to traditional yogurt for those people who have milk allergies or who are vegan.
Soy milk is a product that contains soybeans and some other ingredients such as water and sugars. The soy milk yogurt contains some of this milk, along with the bacteria that convert the liquid into a thick, yogurt texture. Cow's milk contains energy sources such as lactose that bacteria can use to grow.
As soy milk is not an animal product, it has a different nutrient profile for the bacteria. The most common bacteria present in cow's milk yogurt are the Lactobacilli and the species Streptococcus thermophilus. The same types of bacteria can grow in soy milk to form yogurt.
Probiotic yogurts contain bacteria that are beneficial to intestinal health. Soy milk yogurts, as well as cow's milk yogurts, can also support the growth of beneficial probiotic bacteria to some extent. Soy products can be an option for people who suffer from lactose intolerance as the lactose sugar present in cow's milk does not exist in soybeans. As well as being suitable for lactose intolerant people, soy yogurts can also satisfy the vegan lifestyle as none of the ingredients are animal products. Much of the soybeans produced globally are genetically modified, but some producers restrict their ingredients to nongenetically modified beans.
Cow's milk yogurt is a rich source of calcium. Soy milk yogurt producers may add a source, such as tricalcium phosphate, to their finished soy products to give consumers the extra calcium that traditionally is associated with dairy products. As well as calcium, soy milk yogurts may also contain added vitamins, such as vitamin D or vitamin B12.
Homemade soy milk yogurt requires only soy milk as a base and a commercial soy milk yogurt as a starter culture. Mixing the live bacteria with the soy milk begins the process of fermentation that is necessary to create yogurt. The starter yogurt does need to be live to begin the process. Some soy milk yogurts may have undergone pasteurization in the manufacturing process, which kills almost all of the bacteria present.