Though its primary ingredients most often consist of water, flour, yeast, and salt, bread can include a range of ingredients derived from animal products, including eggs and milk. Sometimes they’re added as-is, but other times it can be a little more sneaky. For example, I make pumpernickel bread that has some dry milk in it as a softener. In addition, whey, a milk byproduct, is used in some recipes, and L. Cysteine, a dough conditioner that can lengthen the shelf life of commercial breads, contains animal products, too. Specifically, L. Cysteine can contain hog hair and poultry feathers, and while there are synthetic versions available, they can cost more, so they’re not the default.
