Exploring Cheese Crystals

Marieke Extra Aged Gouda, featuring tyrosine crystals. Photo courtesy of
Yahoo Food, which identified it as one of the “Best Cheeses to Buy Now”
in March 2013, Read the full article here.

It’s interesting that more and more consumers these days are identifying cheese crystals as a feature, not a flaw.

In fact, most every day, at least one customer asks me for a cheese with “those crunchy things” – usually referring to an aged Italian style, such as Sartori SarVecchio or Extra Aged Asiago. Many consumers have figured out that those crunchy bits – known as tyrosene crystals – are often a sign of a bold-flavored cheese and extra aged cheese.

So that’s why a headline in the recent issue of Dairy Foods was so very depressing. Titled: “How to avoid crystals in cheese“, it was an essay by John Lucey, director of the Center for Dairy Research in Madison. Thankfully, upon closer inspection, the article was mostly about avoiding crystals in processed cheese (eew!) and reducing the level of calcium lactate crystals due to poor packaging techniques in plastic-wrapped cheddar. Thank goodness. As this is an industry-based publication, Dr. Lucey did well to help commodity and processed cheese makers take steps to avoid unwanted flaws.

However, for artisan and specialty cheesemakers, crystals – both tyrosene (protein crystals that form in aged Italian styles and some extra-aged Goudas), and calcium lactate (white bumps that appear on extra-aged cheddars), are becoming known more as a feature. And in good news, one of my favorite chief cheese geeks, Dr. Mark Johnson, senior scientist at the CDR, wrote an exceptional and detailed article on “Crystallization in Cheese” in the latest issue of the organization’s Dairy Pipeline — a must read — click here to view.

When I’m trying to explain the difference between calcium lactate and tyrosine crystals, I almost always go to the eternally-bookmarked page of Laura Werlin’s Cheese Essentials. On page 164, she has one of the best explanations I’ve ever read, and I quote it often. Keep in mind this was written in 2007, so Werlin was ahead of her time in appreciating this particular cheese trait:

“A by-product of cheese aging is the breakdown of protein. You have probably experienced this phenomenon but not known what it was. For you, it was when you bit into a cheese and discovered the delightful little crystals that seemed like sugar. To me, these are the ultimate payoff in a grana-style cheese. In almost all hard cheeses, the crystals are the result of the proteins breaking down, a process called proteolysis. The particular amino acid that breaks free is called tyrosine, but to anyone who enjoys those crystals, it’s called a bite of heaven.”

Werlin goes on: “You might also find crystals in cheddar cheese, but these are entirely different. The crystals found in cheddar are generally not the result of proteolysis (which explains why they are not tyrosine) and are instead probably the effects of certain starter cultures. Called calcium-lactate crystals, these tiny white crystals tend to colonize the surface of the cheese and, to the untrained eye, may look as if the cheese is developing some type of white mold. While this is not the case, many cheesemakers, particularly the large manufacturers, have traditionally tired to avoid this. However, because people usually like these crystals, many cheesemakers are no longer discouraging their development.”

At modern U.S. cheese judging contests, both types of cheese crystals are more often being treated as a feature, not a flaw. (This largely depends on the age and education of the judge – I’ve found it’s hard to convince a 70-year old Cheddar cheese grader that calcium lactate crystals are now in fashion).

The American Cheese Society is leading the way on this education. At its annual competition, judges are specifically trained on calcium lactate crystals. In pre-conference webinars, judges are taught that an “even distribution of aging crystals” on aged Cheddar surfaces may be considered desirable, and can even earn a cheesemaker points from the Aesthetic Judge if he or she determines “a pleasant mouthfeel or ‘crunch’ from these crystals if they are evenly felt and seen on the cheese surface.”

That’s good news for us cheese eaters seeking out “crunchy bits” in our cheese. The next time you’re at your favorite cheese shop, be sure to impress the cheesemonger with your knowledge of tyrosene and calcium lactate crystals!