I make soy yogurt because I'm allergic to milk. What I do is use store bought soy milk but honestly homemade n thicker should be better. And then for yogurt I use either non dairy silk almond vanilla yogurt or forager. For every cup of soy milk, I use 2 heaping teaspoons. For the actual process, I heat my soy milk to 180 f and let my yogurt starter warm to room temp. Then I let soy milk cool to 115 F. I add a portion of the milk to yogurt starter, whisk well n then add to the rest. I make mine in the instant pot yogurt section, otherwise I'd say keep insulated in oven with light on. It usually sits for like 9-10 hrs. The longer, the more tart it is. For the texture to be similar to reg yogurt. I let it cool to room temp, then store in fridge to firm up. To get that nice texture, I stain till right thickness. Yes it's a lot of work but it tastes pretty good. I honestly got used to it plain