
How to make homemade lye water for use in recipes such as Pretzels and Mooncakes. Recipe with step-by-step photos. What is Lye Water? Lye water is a food-grade alkaline water used in some recipes to help with texture or colour. For example, lye water gives Pretzels their signature dark brown colour and taste. For Mooncakes, a small amount of lye water is used to give the dough a deep, golden colour.