Soy yogurt is, as the name suggests, a yogurt made from soy milk and the same bacteria used for fermenting cow yogurt, Lactobacillus bulgaricus and Streptococcus thermophilus. Flavors, sweeteners, fruits or chocolate chips can sometimes be added.
Soy yogurt, properties
Soy yogurt is a tasty, plant based alternative to cow's yoghurt that, often, due to lifestyle choices or intolerances, cannot be eaten. This soy product does not contain cholesterol, 100 grams of yogurt brings approximately 3.5 grams of protein, approximately 16 grams of carbohydrates, 176 mg of calcium, but also iron and vitamins A and C (USDA Food and Data Database). Studies have shown that the consumption of soy yogurt has a beneficial effect on the health of the cardiovascular system, since it helps to increase good HDL cholesterol and to inhibit the oxidation of bad LDL cholesterol (Cavallini et al, Lipids Health Dis., 2009). The oxidation of LDL cholesterol is considered one of the main causes of atherosclerosis. Not only that, the fermentation of soy milk makes the yogurt a food with antioxidant action, capable of protecting DNA from free radical damage (Yamamoto et al, Bioscience of Microbiota Food and Health, 2019). In fact, it is the fermentation that modifies some antioxidant substances present in soy milk, the isoflavones, making them more easily assimilable by the body (Kano et al, Journal of Nutrition, 2006).
Soy yogurt, allergies
Soy allergy is a condition that is not very common but has already been observed. However, it has been shown that the fermentation process, to which soy milk is subjected to produce the yogurt, reduces the allergenic potential of the final product (Rizzo et al, Nutrients, 2018). Soy yogurt does not contain lactose and therefore can also be consumed by people who are lactose intolerant.
Soya yogurt, self-production with the yoghurt maker
For those who love to self-produce yogurt and to have maximum control of the ingredients, here's some good news. Even soy yogurt can be prepared at home and with excellent results. If you have a yogurt maker, the procedure is very simple. Pour a little soy milk into the jar of the yogurt maker and add the live yogurt cultures or 4 tablespoons of yogurt previously prepared. Pour in the rest of the milk and mix well. Insert the jar into the yogurt maker and run the program. As for how long to leave the yogurt maker running, a lot depends on the type of milk and the cultures. Generally, after 7 hours the yogurt should have formed. If you find the yogurt still liquid, you can leave the yogurt maker running for a couple of hours, but if the yogurt has formed a whey on the surface, then the working time of the machine should be reduced.
Soy yogurt produced without yogurt maker
If you don't have a yogurt maker, the preparation varies slightly. Heat the milk up to 40° C. Pour the milk into a jug and add the live cultures or 4 tablespoons of previously prepared yogurt. Close the carafe with its cap or saucer. Wrap the jug in a blanket and store it away from drafts, in a warm place like the oven. Let it rest for 8 to 10 hours and the yogurt will be ready. The prepared yogurt can be used as a starter for the next yogurt, just take 4 tablespoons and add them to the new preparation. Over time, however, the action of bacteria tends to reduce and the yogurt may not be perfectly formed. It is then the case to start again with a new packet of live cultures. These live yogurt cultures are easily purchased in chemist’s shops, but also in specialized shops and organic supermarkets. Even better if you can find the cultures for the preparation of yogurt added with probiotics.