Parmentier (1737-1813), contrary to popular legend did not "invent" the potato, which had been known and cultivated in France since the 16th century, but he was an enthusiastic propagator of it. La Parfait Boulanger~describes the process of making bread in practice at this period: hand-kneading the dough, fermenting with natural leavening, shaping the loaf, and baking in brick, wood-burning ovens. The book also refers to something new: adding salt to the dough, unusual until that time due to its high price. It was realized that salt improved the texture of the dough, allowing it to rise higher. Parmentier also referred to brewer's yeast, which a Parisian baker had first added to leaven in 1665 in the production of a loaf called pain mollet.