Step 1. Preparation of the yeast

The yeast Saccharomyces cerevisiae is separated in a sterile manner from the medium made from the wort, which was providing it with the essential elements for growth. The growing yeast is then seeded first into tubes and then into Erlenmeyer flasks containing sterile wort. Two flasks are then used to inoculate the wort in a large 2 000-liter vat in which the yeast replicates for forty-eight hours, forming the yeast starter.