Just as you can create a buttermilk alternative by souring cow's milk, you can mix soymilk with an acidic component to create dairy-free buttermilk. Since there aren't any pre-made buttermilk alternatives available on the market, being able to make your own vegan buttermilk opens the doors to making a variety of delectable dishes ranging from salad dressings to pancakes. Additionally, your homemade “buttermilk” contains enough acidity to add flavor to your favorite dishes while performing the same chemical functions as traditional buttermilk.
Measure 1 tablespoon of an acidic ingredient such as apple cider vinegar, distilled white vinegar or lemon juice for every cup of soymilk that you're using. Avoid using darkly colored vinegars such as balsamic or red wine, since they can color your soy buttermilk and affect the appearance of your dish.
Whisk the mixture vigorously to combine the ingredients. Allow the mixture to stand for at least five minutes before using it. To give your dairy-free buttermilk a tangier flavor, place the mixture in the refrigerator for two to three hours before using it.
Swap your soymilk mixture for buttermilk using a 1 to 1 ratio. Since soymilk has a similar thickness and creaminess to cow's milk, you can use an equal measure as a substitute without compromising flavor or texture.
If a recipe calls for buttermilk for something that requires a thicker, creamier texture, such as dressings or dips, use a thicker medium, such as cashew cream, for your substitute. Make your own by soaking raw cashews in an equal amount of water for 30 to 60 minutes. Drain and discard the soaking water and place the soaked cashews in a blender or food processor. Add 1 cup of water and 2 teaspoons of lemon juice for every cup of cashews and blend it until it's smooth; this makes roughly 1 1/2 cups of dairy-free buttermilk per cup of cashews.
You can use this method with other dairy-free milks, including rice milk or almond milk. Soymilk yields the best results, however, since it's one of the heartiest milk alternatives.
The type of soymilk you're using makes a difference. Plain, unsweetened soymilk is the most versatile kind. If you're baking with your soy buttermilk, you can use sweetened, flavored soymilk such as vanilla soymilk, but you might need to adjust some of your other ingredients to account for the added sweetness.