White spots (crystals) present in dry-cured ham are evidence of long, natural ripening. It is an amino acid, tyrosine, which is formed during the maturing process by breaking down proteins into smaller building blocks, amino acids. 

IS THIS A JAMON DEFECT?

No, it is not. Conversely, the presence of white tyrosine crystals is evidence of the naturally long maturation process that is so important for creating an intense matured "a curado" jamon flavour. Not surprisingly, the highest quality dry-cured hams often have these white crystals showing the best quality.

Tyrosine is most often found in jamón ibérico, but you can also find it in high quality jamón serrano ( pictured above - boneless jamón serrano Gran Reserva 15 months )

DOES TYROSINE AFFECT THE ORGANOLEPTIC QUALITIES OF JAMON?

When it comes to the organoleptic qualities affecting the senses such as taste, colour, odour, and feel, we cannot say tyrosine affects these in jamon. Some larger crystals can crunch when bitten, but tyrosine does not affect the tasting experience of jamon.

TYROSINE, MITES AND JAMÓN

Tyrosine crystals are not undissolved salt crystals, as people often think, and they are neither any stage of any parasite. The crystals should neither be confused with any mites that can sometimes appear on the surface of the jamon. The mites move on the surface and resemble moving white grains of sand. They are never inside the meat.