The black Iberian pig has a diet of mainly grass and acorns. The acorns contain a high level of monounsaturated fatty acids that influence the rate of blood cholesterol. These help to reduce 'bad cholesterol' and to increase 'good cholesterol'. They are also a source of vitamin E, an antioxidant that favours the elimination of free radicals responsible for ageing. A mild salting process allows the stabilization of the enzymes and the perfect preservation of the meat. The hams and shoulders of Joselito are characterised by their low salinity, nearly to be considered sweet.

In winter, in natural dryers, the salt migrates slowly through the meat causing the loss of water.  In spring and summer, "the sweating of the ham" is produced in natural dryers, the fat melts and penetrates into the muscle fibres.  When autumn arrives, the pieces begin to cure in natural underground cellars, with constant temperature and humidity. It is on the cellar where the Joselito ham and shoulder refinement takes place. The meat will remain in this place for several years to achieve perfect organoleptic quality.