Mustard making is a multi-step process. The seeds must first be checked and cleaned. They are then flattened (the bark is split) so that the almond can absorb the verjuice, wine, or vinegar in which they soak and are kneaded for several hours. Millstones then grind them before a centrifuge separates the seed coats from the paste obtained. This sieving or bolting operation precedes the storage of the mustard in vats for 48 to 72 hours for its maturation and the dissipation of its bitterness. Finally, a final mixing by deaerator eliminates the air molecules that oxidize the mustard and homogenizes the paste.