All you need is your favourite store bought soy milk, some dairy-free, starter culture and agar agar to thicken - be sure to choose a soy milk, with no additives or preservatives. I promise, once you start making your own soy yogurt at home, you’ll find yourself never wanting the overly sweetened, and far too pricey supermarket varieties again!
While non-dairy milks will culture and produce a sour yogurt-like taste, they won’t naturally tub-set without a little added thickener. I get a great, spoonable ‘yogurt’ with agar agar. See our previous recipe posts for nut milk yogurt or coconut yogurt thickened with gelatinfor more on thickening non-dairy milk yogurt.
In traditional dairy milk yogurt, the bacteria in starter culture thrive on the sugar (lactose) content, naturally found in milk. The bacteria populating your soy milk must have something to feed on to allow the culturing process to take place. A little bit of sugar is enough to kick start fermentation. Don’t be afraid of this, the sugar is not for you, and it will be consumed by the hungry, healthy, bacteria. If your soy milk already contains sugar you don't need to add more.
1 litre carton of soymilk (or as much as your yogurt maker can hold)
Starter culture (quantity specified)
1/2 - 1 teaspoon of powdered agar agar
1 teaspoon of white sugar
1. Pour the soy milk into a large saucepan.
2. Add the sugar and agar agar powder and stir to combine.
3. Gently heat the soy milk to 190⁰F (87⁰C) and hold the temperature for 10 minutes. Do not allow the soy milk to boil. Soy milk expands while it heats, so you can visually gauge when it is about to boil.
4. Remove from the heat and let cool to below 108° F (42° C). Note: Starter culture will only thrive in a narrow temperature range, too cool and it will go dormant, too hot and it will die. So be sure to allow the soy milk to cool before adding the starter culture. Don’t worry if the soy milk has gone cold. (forgetting about it is very easy) It will heat up again in the yogurt maker and activate the starter culture.
5. Add your preferred starter culture and gently whisk it in.
6. The milk is now ready to begin fermentation. Put the lid on the glass yogurt jar and place into your yogurt maker.
7. Switch the yogurt maker on. Set the temperature to 38° C, set the timer to 24-hours.
8. After 24 hours the fermentation is complete.
9. Place the soy yogurt in the fridge for at least 6 hours to cool and set.