Gluten-free sourdough. Contains 3 bags of 16 g. 16 g of yeast is ideal for 500 g of flour. Cream of tartar is a leavening agent. It is an excellent alternative to chemical yeast and can be used to make cakes, pizzas and bread. It is essential for all those intolerant to yeast and for those who follow a vegetarian diet. Produced in a factory where soybeans are also used.