Add water, soy milk powder and sugar to a high-speed blender. Blend for 3 minutes (The temperature will be around 166°F)
Add the agar powder and blend for 30 seconds longer (the temperature will now be around 172°F)
Allow the soy milk to cool down to 110°F (you can speed this process up by placing the blender carafe into a bowl of ice water).
Once the temperature is down to 110°F, add the probiotic powder or vegan culture and whisk into the soy milk (don’t blend it)
Pour the soy milk into two 16-ounce glass jars.
Close the Instant Pot, set to sealing, and select the “yogurt” setting for 14 hours.
Remove the jars from the multi cooker, cover with lids, and allow to cool on the counter before storing in the refrigerator. Though firm out of the Instant Pot, this is best served after two or more hours in the refrigerator. Enjoy!