How Cheese is Made Part III: Affinage, or the Art and Science of Aging Cheese

wheels of goat gruyere Previously:

How Cheese is Made Part I: Milk How Cheese is Made Part II:  From Milk to Curd

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Cheese is preserved milk. Though the process of cheesemaking has evolved over thousands of years, with all of the technological innovations of the post-industrial age, this fact remains. The art of preserving milk is, as we've seen in the past couple installments of this miniseries, an incredibly multi-faceted, complex process....and that's why when people ask me whether or not I'd like to make cheese I always laugh and say - no way, I've learned way too much about what it takes to make cheese successfully.

The problem of storing and curing cheese is both an empirical question as well as an economic one for a cheesemaker. Fresh cheeses go in and out the door quickly, bring in income, and do not require much in the way of storage at all. On the other hand, if a cheesemaker decides to make, say, an aged cheddar or gouda, she must consider where and how to store the cheese as it ages. Space must be calibrated to production levels and then a cheesemaker must factor in how to regulate the temperature and humidity to maximize the quality of the aged cheeses. Aging cheese is like inventory sitting in a warehouse - precious saleable goods with all of the associated risks.

The Aging Process

aging cheddar cheeseFresh cheeses are just that - freshly made and typically out the door within a few days or weeks. For cheeses like fresh chévre or fromage blanc, aging is typically something to be avoided and the primary concern for a cheesemaker is simply preservation of these cheeses in their fresh state.

But the majority of cheeses you'll see at your local cheese shop have been stored and aged to some degree or another. What's happening when cheese ages? Any number of things are going on all at once. First, compacted cheese curds are losing moisture. This process causes the cheese to become firmer in texture. Perhaps more importantly, millions of microorganisms of all kinds are doing their work on the cheese, transforming it into the end product that consumers will enjoy. Without going into the dry details too much, suffice it to say that proteins and fats break down over time, chemically transforming. Gases are given off. In reality, the whole thing is quite full of exciting non-stop action, albeit on a microscopic level. If you're familiar with watching you know that watching cheese age is somewhat like watching paint dry... best to watch the time lapse video. What's happening, in essence, is that flavor and texture is developing over time.

Even though a cheese is essentially just sitting there while aging, it still requires the cheesemaker's constant attention. Washed rind cheeses, for example, must be bathed periodically (usually every couple of days or so) in wine, brine solution, beer, or whatever solution the cheesemaker has chosen. Some cheesemakers may periodically wipe the rinds of aged cheeses with olive oil or other fat to help preserve the rinds and keep them from splitting. Others elect to coat their cheeses in a variety of substances such as wax, or modern day edible resins, which alleviate the need for some of this labor intensive care. In addition to rind care, cheeses must also be flipped and turned periodically so as to ripen evenly - in Europe, robots are employed to perform this duty in massive storage facilities.

Industrial sized cheesemaking operations generally wrap their cheeses in plastic and the blocks are stored that way as they age (if you've ever visited the Tillamook plant you have seen this process in action). This accomplishes a couple of things - it helps prevent moisture loss, and it alleviates the need for maintaining the surface rind of the cheese block as it ages. If you've ever wondered how it's possible to make an eight year old aged cheddar, this is how. If the cheese were left out in the open air for eight years it would be a dessicated pebble!

Cheese Caves

There is romance in the image of a cave filled with maturing cheese. If you travel to Roquefort, France, you can experience this firsthand. These particular underground caves, actual holes in the earth that have existed for millenia, have been adapted by the French to fit the purpose of aging cheese. But true underground earthen cheese caves are more the exception than the rule - what most cheesemakers refer to fondly as their 'cave' is in actuality a refrigerated, humidified unit of some kind or another that holds cheese.

One of the most innovative developments in affinage in the US are the newly constructed Cellars at Jasper Hill Farm in Vermont. Mateo and Andy Kehler of Jasper Hill Farm have built a massive 22,000 square foot aging facility that has enabled them to become the center for cheese aging in the state. Vermont's cheesemakers have been sending their cheese to the caves, where their wares are carefully maintained until they achieve their maximum potential. While new to the US, this model is more common in Europe, where professional affineurs like Herve Mons or Pascal Beillevaire are known for their expertise in ripening cheese to perfection. Cool job, eh?

What Could Happen?

cheese agingWhile it may seem as if the aging process is a rather benign period of time when a cheesemaker might fact that's far from the case. Temperature and humidity in the facility must be carefully monitored and maintained so as to avoid problems. A finished cheese may end up too dry or too crumbly for any number of reasons, one of which is that the temperature was too high in the aging room, or the humidity was too dry. Poor cheesemaking practices will reveal themselves during the aging process - for example, a cheese that has not been properly drained while being made will have excess acidity (from the leftover whey). Improper combinations of microorganisms introduced in the vat or via contamination at any point in the make process can produce exploding cheeses. Strange molds and bacteria introduced to the storage unit through chance or poor management practices can upset the delicate balance of conditions and ruin the cheeses altogether. Cheese mites are yet another unwelcome companion in the aging room - these insects burrow into cheese rinds (though they are specifically introduced when making cheeses like Mimolette).

Whew. A cheesemaker is constantly on the lookout for all of these problems and a host of others. Cheese sitting on the shelf is like money in the bank and it's critical to the cheesemaker's operation that the product mature to an optimum level and then move out of the cave and into customers' hands.


From maintaining healthy pastures, to animal care, to ph control, to monitoring humidity and temperature, the process of making cheese is much, much more than simply playing with milk or handling curds. A cheesemaker must be a jack of all trades - a keen analyst, a science guru, a goat whisperer and a troubleshooter - an even then, they'll need a lot of help to make the whole operation run smoothly. I'm truly in awe of those folks that make great cheese day in and day out. Time and technology have streamlined the processes but the complexity of making great cheese remains an art practiced by many but mastered by few.

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University of Guelph Cheesemaking Site