We don't know what yield or purity you need, because we don't know your application. Anthocyanins, and other things, will come out of soft berries with water, or just by crushing berries and filtering. (We're also left wondering what berries you'll use -- strawberries, blueberries, blackberries?) If you want to lower the pH at home, white vinegar is a good choice. If you need a base, household ammonia is probably adequate.