Yeast Substitute VeganVegetarian ★ ★ ★ ★ ★ Be the first to rate this recipe Ingredients 1 tablespoon baking soda ⓘ 1/2 teaspoon unbuffered vitamin C powder (ascorbic acid) or 1 tablespoon baking soda Instructions Use one of the above combinations in place of one tablespoon yeast.