The Process of Aging Cheese

Learn about the science, art and magic behind this crucial aspect of cheesemaking.

We don’t have a word in the English language for the process of aging cheese, or the work of a cheese ager. So, we tend to borrow the French terminology. In French, the word affinage means “to refine” or “to complete”. The term comes from the Latin word ad finis, meaning “towards the limit”.

An affineur ages cheese. “My mom introduces me either as a cheesemaker or cheese monger, and I don’t quite do either of those things,” says Josh Windsor, who works as an affineur and caves manager for Murray’s Cheese, at its cheese caves in Long Island City, NY. His work occupies “the weird place between the make and the sale of the cheese.” He also calls himself a “mold farmer.”

Windsor sees his work as helping the cheese reach “its most perfect form,” he explains. “Most people don’t think about it—or they think cheese just sat there—but cheese takes a lot of hands-on care.”

Affineurs are responsible for bringing young cheeses to maturity by inoculating, washing, massaging, piercing, turning and caring for wheels until they reach the peak of deliciousness. Some cheeses get vacuumed (yes, with a vacuum cleaner!) to help control rind growth. Others get sprayed with spirits or showered in herbs. Whether cheeses age for days, months or even years, this crucial stage is where it takes on the ultimate flavor, texture and personality.

Like all artisanal cheese in the U.S., we borrow techniques and tradition from Europe, but then make them our own. “We inherit French traditions and perspectives,” explains Windsor. “But as American producers, we have opportunities to create variations or changes on traditions—to explore—and to imagine new ways to think about cheese.” During the aging process, we can think about cheese in new ways and create new experiences of flavor and character. Between making cheese and selling cheese, it becomes something unique and wonderful.

Why Age Cheese?

Peter “PJ” Jenkelunas moved from Hudson Valley, where he made cheese at Old Chatham Sheepherding Co., to New York City to work in Murray’s Caves nearly a decade ago. Now he is the director of affinage at Murray’s, responsible for every aspect of its caves program.

He sees his work as being “all about flavor.” Jenkelunas uses his background in food science to “let the enzymes and microbes in the cheese do their work and create something more unique than if you had just a fresh product,” he explains. His team and the caves can create “great depth of flavor. Harnessing the power of microbes to create unique flavors is inherently fascinating to me.” 

To say cheese is a living, breathing thing not just a lyrical turn of phrase; cheese is very much alive and constantly evolving. Cheese begins with milk, which comes from cows, goats and sheep, which graze on grass, hay and wildflowers. Excellent cheese starts with high-quality milk, but expert maturing takes the cheese to the next level, really making it sing.

First, aging cheese preserves milk, which has helped feed populations through long, cold winters for millennia. Second, it makes cheese unfathomably delicious. Gooey brie, peppery Roquefort with its blue-green veins and sharp farmhouse cheddar all begin as fresh milk, then become nearly flavorless curds. It’s the aging process that make these cheeses culinary masterpieces and iconic staples.

After cheese is made, it continues to change: it loses moisture, proteins and fats break down, and rinds—the cheese’s outer crusts—develop, as do increasingly complex textures and flavors. Keeping the cheeses in a controlled environment allows the right microbes to work their magic (also called microbiology) on the proteins and other components of the wheel. Affinage requires a deep working knowledge of bacteria, molds and yeast strains and the ability to encourage the growth of some, while slowing or stopping others.

Does that have to be in a cheese cave? The room for aging cheese is called une cave in French, or cellar, and although cheese may be aged in a cave, it may also be matured in an abandoned railway tunnel, a trailer or just a really high-tech walk-in refrigerator. What matters is that humidity, temperature and air movement can be precisely regulated in order to control bacteria and mold growth.

Murray’s caves are fancy, giant, high-tech refrigerators where thousands of wheels of cheese mature in the ideal environment. These are specifically calibrated so that temperature, humidity and microbial activity can all be controlled and monitored with the greatest precision. The caves give Jenkelunas and his team the ability to “move things around, change things and take cheeses in new courses and new directions.”

The Power of Aging Cheese in a Cave

At Murray’s, each cave is calibrated especially for different cheeses. In the bloomy cave, cheeses like brie, camembert, Brillat Savarin and Humboldt Fog develop downy white rinds. Slightly cooler and drier than the other caves (at about 48 degrees F, and a relatively low humidity around 85%), it’s here that the yeast-like mold Galactomyces candidus and Penicillium camemberti grow. The former is off-white in color and creates a wrinkly rind that looks a little bit like a brain. This type of rind can be found on cheeses such as those from the Loire Valley in France, like Crottin, Selles Sur Cher and St. Maure.

Penicillium camemberti is a strain of fluffy white mold that appears like a white downy, velvety coat on cheeses in the same family as brie or camembert. Both are responsible for breaking down the proteins in cheese and significantly contribute to the final texture and flavor.

In the Murray’s bloomy cave, the unique environment fosters the development of molds and yeasts that are added to milk during the cheesemaking process. The company purchases much of its cheese young, or “green,” meaning rindless, and develop the rinds carefully and where optimal conditions allow the mold to flourish.

Rinds “bloom like a field of microscopic flowers,” says Windsor, and the cheeses are patted down and flipped regularly to ensure even ripening.

Spring Brook Farm’s Tarentaise, comté and Gruyère are some of the wheels that mature in the Alpine cave, where there’s “a more hands-off approach,” says Jenkelunas. Here, the cheeses (affectionately called “gentle giants”) are washed on a regular basis for the express purpose of keeping the rind from drying out as well as prohibiting unwanted mold growth and encouraging beneficial microbial growth.

The washing done in the Alpine cave is much gentler than the scrubbing that occurs in the washed rind cave, where, just like the name, the cheeses are washed in a salt solution—typically water, brine or alcohol—which inhibits the development of mold while promoting yeast and specific bacterial growth. These cheeses are imbued with a distinct, often powerful flavor. This cave involves the most work (all that washing!) and yields delicious washed rind favorites like Murray’s Cave Aged Reserve Greensward (a collaboration with Jasper Hill) and perfectly stinky Epoisses.

Less intensive intervention happens in the natural rind cave. Cheeses here are encouraged to express the microbes present in the cheese as well as those present in the cave, which means it takes on a unique Long Island City terroir. These cheeses are an expression of place in terms of both the cheese’s origin and its time spent in the caves at Murray’s. Because of this, the microbial variety of the natural rind cheeses is constantly changing. Murray’s Cave Aged Original Stockinghall Cheddar and many blues mature in this cave. “Every cheese cave is completely its own; completely unique,” says Jenkelunas.

Creating New Cheeses Through Affinage

Windsor’s “excitement is always based on learning something new, and challenging ourselves to not just replicate things but push outside our comfort zones,” he says.

Murray’s Affineurs age existing beloved cheeses, but their creativity really shines when it comes to Caved Aged Originals They often collaborate with top dairy scientists and local creameries to develop new cheeses from original recipes and have a hand in their entire process through the final step of cave aging in their caves. They shepherd these brand-new wheels through make, treatment and care.

There’s no better example than Stockinghall Cheddar, which won Best of Show at the American Cheese Society competition in 2019, a huge accomplishment for a new creation. The cheese is made in collaboration with Old Chatham Creamery, which crafts the young wheels. They are then wrapped in cloth and aged for at least a year in Murray’s natural rind cave. Over time, meaty bacon and sour cream flavors develop, along with a bright finish of pineapple. It’s well-balanced and rich, with tons of depth and a texture that is both fudgy and crumbly.

The cheese was such a hit that the afineurs developed new variations, including Murray’s Cave Aged Stockinghall Reserve Blue, studded with gorgeous blue veining, and Murray’s Cave Aged Reserve Extra Aged Stockinghall, which gets an extra six months of age for a slightly firmer texture and notes of mustard and buttered mushrooms.

We can create “a completely unique product just by putting a cheese in a new environment,” Windsor says.

Murray’s Cheese caves doubles as their fulfillment center, so they are also breaking down cheeses from around the world. Aging cheese in New York City is a “true melting pot of cheese,” Windsor believes. “We can take cheeses in new courses and new directions.” With affinage, so much is possible.

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