Many people are familiar with “crunchies” in well-aged Alpine and cheddar-style cheeses. Annelies is no exception, with these crunchy crystals commonly detected as the cheese nears a year of age. So what exactly are these crunchies?

As cheese matures, the carbohydrates, proteins, and lipids are broken down by microbes into small compounds. Proteins are composed of amino acids linked together into peptides. During protein breakdown (a process called proteolysis), these linkages are broken, releasing ammonia, small peptide fragments, and free amino acids. Although a variety of free amino acids have been detected in aged cheese, tyrosine is the amino acid most frequently associated with crystal development (i.e., the crunchies). These crystals develop as tyrosine molecules collide with one another; the more collisions occur, the more tyrosine molecules are attracted to the site, and eventually the tyrosine loses solubility (no longer dissolved) within the cheese matrix. At this point, we detect the crystal when we eat the cheese, or in other words, we get that satisfying crunch in each bite! The longer a cheese ages, the more extensive the proteolysis, which is why we don’t detect any crunch in a young version of Annelies.

As of now, more research is needed to confirm the mechanism behind the development of tyrosine crystals. However, data (albeit circumstantial) have shown that Lactobacillus helveticus (a type of bacteria commonly active in maturing cheese) is closely associated with tyrosine crystals. L. helveticus cannot make or break down tyrosine, so tyrosine is released as this bacterium utilizes peptides created during proteolysis. L. helveticus may not itself be active in the cheese—its peptidase enzymes may remain active even once the bacterial cells have lysed. Tyrosine crystals likely form in discrete patches, either around L. helveticus or where it had once thrived. So these crunchies are like little, delicious gravestones.

If these crunchy crystals are your thing, you should know that this process can also be found in extra aged Goudas such as Roomano (aged for 3 years) as well as Clothbound Cheddars such as Montgomery’s Cheddar from Neal’s Yard Dairy (aged for 12 months minimum) or our very own Stockinghall Cheddar.