Made from raw sheep's milk, Azeitão is produced by a small number of farmhouse dairies in the Arrábida Mountains of southern Portugal.

The origins of Azeitão can be traced to Serra da Estrela, another cheese made in northern Portugal. Cheesemakers from that area brought their skills and traditions to the Azeitão, Setubal, Palmela and Sesimbra regions where Azeitão is made.

The milk for Azeitão is coagulated using a vegetable-based rennet made from the stamens of the cardoon thistle flower. This is unusual, especially today when the majority of commercial cheesemakers use either an animal-based rennet or one that has been synthetically produced. The use of thistle rennet is traditional in some Mediterranean regions, however it is much more challenging for the cheesemaker to use, and makes it difficult to produce a consistent cheese - another reason for its decline.

Although Azeitão is made year round, the best season for production tends to be between April and Augustwhen the sheep are browsing the summer vegetation. There is frequently a shortage of cheese in September and October.

The texture of Azeitão is smooth and velvety when ripe, becoming harder and drier as the cheese ages. The rind is a rust-brown-colored, sometimes dotted with patches of white mold. The interior paste is ivory-white and yielding.

Aromas can be fairly pungent and sheepy - characteristics that continue into the flavor of the cheese. Azeitão, like other cheeses that are coagulated with thistle rennet, tends to have a unique, slightly sour (sometimes verging on bitter) taste.

Although this sounds unpleasant, these flavors are balanced by the sweetness of the sheep's milk and herbaceous, savory and vegetal notes.