So, today I learned how to create a buttermilk substitute in a whole foods way and it’s very simple. Add 1 tbsp vinegar to 1 cup of non-dairy milk. Let it stand for 5 minutes. The milk curdles immediately. You can also use lemon juice if you don’t have vinegar.
When using buttermilk in leavened baked goods it is necessary to lower the amount of baking powder because buttermilk has more acid than regular milk. For example, for every cup of buttermilk used in place of regular milk, you reduce the amount of baking powder by 2 teaspoons and add 1/2 teaspoon baking soda.