The curdling of the milk is an indispensable step in which the milk’s most abundant protein, casein forms a colloidal solution in the whey. This process is relatively easy thanks to the rennet’s action. In La Serena cheeses, it is obtained by macerating dried wild thistle flowers, which is the plant shepherds have traditionally used in this process. It is a very traditional method: starting with the fresh milk, as is the case of most cheeses of the best quality, the curdling takes about an hour until the paste is compact. The shepherd checks how compact it is by sticking an olive tree stick with four prongs into the paste. When it stands up on its own, this means that the curdling is finished. Next, following the traditional method, the paste is placed on an inclined table, the “exprimijo”, in order to separate the whey. The esparto belts are placed on this table, too, and the paste is then poured into them. As the whey is separated, the shepherd will tighten the belts so that the wheels gain in height. The wheels are salted on one side and then the other is not salted until the next milking. Wait 12 hours before removing the molds and placing the wheels on pine or oak shelves. After two days, the wheels are completely removed from the belts and they should be rotated daily. The cheese continues its curing process at a constant temperature and humidity.