Avoid milk allergies, lactose intolerance and animal products in all your recipes by converting them to use non-dairy substitutes. Buttermilk from cow's milk has a tang which adds both flavor and acid to recipes. A non-dairy buttermilk substitute must also contain both flavor and acid to be effective in cooking.
Non-dairy Milk Substitute
Soy milk appears on shelves even in mainstream grocery stores as a non-dairy alternative to cow's milk. To use soy milk to replace buttermilk, you must add an acid to the milk and allow it to sit for several minutes to begin to chemically "curdle." Combine 1 cup of soy milk with 1 tbsp. of vinegar or lemon juice and let it rest for 15 minutes before adding to your recipes. Use any non-dairy "milk" such as rice milk, oat milk or almond milk instead of soy milk if desired, following the same proportions of acid to "milk."
Yogurt Alternative
Yogurt made without cow's milk is available at natural and health food stores and on the Internet. These yogurts often have a base of soy milk which has been cultured to produce the tang of cow's milk yogurt. Use non-dairy soy yogurt instead of regular yogurt mixed with soy milk to make a tangy buttermilk replacement. Mix 2/3 cup soy yogurt with 1/3 cup of soy milk until blended smooth, and use it to replace 1 cup of buttermilk in your recipes.
Tofu Buttermilk Replacement
Use tofu as the base for making a buttermilk substitute. This requires the use of a blender to thoroughly mix together the tofu and water so the resulting non-dairy "buttermilk" has no lumps. In the jar of a blender or food processor, Baking 911 recommends combinin: ¼ cup silken tofu, ¾ cup water, 1 tbsp. lemon juice or vinegar and a pinch of salt. Puree this together on a low speed until smooth. Let it sit for 10 minutes before adding to your recipes.