On Food and Cooking

Cheese  Crystals

Cheeses usually have such a smooth,
luscious texture, either from the beginning
or as a hard cheese melts in the mouth, that
an occasional crunch comes as a surprise.
In fact a number of cheeses develop hard,
salt-like crystals of various kinds. The
white crystals often visible against the blue
mold of a Roquefort, or detectable in the
rind of a Camembert, are calcium
phosphate, deposited because the
Penicillium molds have made the cheese
less acid and calcium salts less soluble. In
aged Cheddar there are often crystals of
calcium lactate, formed when ripening
bacteria convert the usual form of lactic
acid into its less soluble mirror (“D”)
image. In Parmesan, Gruyère, and aged
Gouda, the crystals may be calcium lactate
or else tyrosine, an amino acid produced by
protein breakdown that has limited
solubility in these low-moisture cheeses.