The Homemade Vegan Pantry. And it's pretty fortunate, because while now there are marvelously tasty vegan yogurts available, they are also fairly expensive, and this recipe gives you a nice quart of yogurt for the price of an almond milk carton.
The key thing to remember is not to add the yogurt in Step Two before the contents of the jar cool enough to allow the cultures to do their thing. Beyond that, easy peasy.
1 container unsweetened almond milk
1/3 cup cashews
2 tbsp cornstarch
1/2 tsp agar flakes
2 heaping tbsp vegan yogurt (I use the last of a previous batch; to start the process, you can buy a little container of Kite Hill plain almond yogurt, or any soy yogurt, and use that.)
Place almond milk, cashews, cornstarch and agar flakes in blender and blend until smooth. Pour into saucepan, place on stove, and whisk while bringing to a simmer. Cook for about 3-4 minutes, until the mix thickens somewhat. Then, turn off the heat and pour the contents of the saucepan into glass jars (I like larger ones.) Place the jars outdoors or on the counter until they chill to 110 degrees (warm, but not hot - so that you can put a finger in the mix comfortably.)
When the contents have chilled enough, add the vegan yogurt and mix a bit. Then, close the jars and place them somewhere warm, at about 105-110 degrees. We have an old-fashioned oven, so we just place it inside with the pilot light on; you can put it in a modern oven and turn it on and off, or put it in a dehydrator at a very low temperature, or outside if it's warm. Leave it in the warm space for about 8 hours, then retrieve and place in fridge. The yogurt will continue to thicken in the fridge.