Use a quart of homemade soy milk. Boil your milk and then let it cool off down to 108F/42 C.
Optionally, pour an unopened quart bottle of store-bought soy milk into your Instant Pot.
Add three tablespoons of the soybean soak liquid you saved before as the starter. You can also use some yogurt starter you have saved from the other batches if this is not the first time you make yogurt.
Stir the mix vigorously remembering to add the salt.
Set your Instant Pot to "Yogurt."
Fifteen hours later, you'll find gorgeous, creamy, vegan soy yogurt.
Strain the yogurt using the provided screen to get rid of the excess liquid.
Refrigerate for +8 hours
Add your favorite fruit or cereal.