Queso de La Serena is a cheese made from Merino sheep milk in the comarca (district) of La Serena, in Extremadura, Spain. The pure sheep milk is curdled using a coagulant found in the pistils of cardoon (Cynara cardunculus). This ingredient lends a light bitterness to the otherwise slightly salty taste. It is aged for at least sixty days. When the cheese has a creamy consistency in the centre, it is traditionally eaten by slicing off the top and scooping out the inside with a spoon, and it is known as Torta de la Serena. If it is allowed to mature further it becomes harder, develops a stronger taste and is known as Queso de la Serena.