Desem (pronounced DAY-zum) (Dutch for "leaven") is a type of sourdough starter made from whole wheat flour, spelt flour or other flours (such as kamut, durum and tritordeum) and water. Desem is essentially a 100% whole grain pain au levain, done in the old French way for those who do not prefer their bread sour. Desem bread has a strong following in the natural foods community, where it was largely popularized by vegetarian cookbook author Laurel Robertson.