Let’s talk blue cheese. Blue cheese is one of those preserved foods that even home preservers are hesitant to try making themselves. The main ingredients are deceptively basic – milk, culture, rennet. Then comes the penicillin mold. Eeeeewwww! Why would someone voluntarily add mold? And isn’t penicillin what you take for strep throat?? What if something goes horribly, horribly wrong???

Everybody calm down. This is part where I remind the reader that we’ve been eating this stuff for thousands of years, well before modern sanitation. Gorgonzola (now from Italy) is ancient, dating back to the 800s AD. Roquefort (now from France) is in documents as far back to 79 AD(1). Like other cheeses, blue cheese can be made with cow, goat, sheep and other milks. Traditionally aged in caves which control the temperature and humidity, the mold component was most likely a natural by-product of the aging process. Since the blue Penicillium roqueforti and Penicillium glaucum occur naturally in the environment, certain cheeses may have inadvertently had the right moisture and temperature conditions for the molds to prosper. And it tasted good to the makers, so people kept on making it.

Blue cheese is known for it’s piquant, pungent, earthy flavor. In addition to the distinctively tangy penicillin mold, blue cheeses are also know for hosting several secondary bacteria and molds, namely Brevibacterium linens, Penicillium candidum and Penicillium camemberti. B. linens create a red wash on cheeses and are responsible for that “stinky feet” smell, as well as taleggio, limburger and munster cheeses. P. candidum and P. camemberti are famous for the white mold exterior and soft runny interior of brie and camembert cheeses, and they have the same effect on blue cheese, softening the cheese and giving it that sharp whiff of ammonia. You know you love it!

But how the heck do you make blue cheese at home? If you make cheese often, you’ll discover that the cheesemaking process is remarkably similar from cheese to cheese. Warm the milk, inoculate it with culture, add the rennet to coagulate the milk, cut the curds, develop the curds, then strain, salt and pack the curds in a cheese form. Blue cheeses add mold sometime during this process, depending on which style of cheese being made.

These days you can order a “pure” blue cheese mold strain from a cheesemaking supply. But I cheat. I buy an ounce of my favorite blue cheese from the store, pop it in the blender with water, then add it to the milk mixture. Like your blue cheese super stinky and runny, mild and nutty, or firm and pungent? Just buy and use that type of blue cheese. I often dig through the “leftovers” basket at the cheese shop for my ounce. The advantage of using an existing blue cheese is that it comes pre-populated with all the primary and secondary critters that will rapidly take over your new wheel of cheese.

The aging process, which takes 2+ months, is a little freaky. Remember the part about aging in a cave? You’ll need to make your own cave as best you can. Blue cheese likes to be aged at 85% humidity, between 55-65 degrees. My cave solution is super lo-fi. I use a recycled 5 gallon food-grade plastic bucket and lid (my bucket lived its former life with kosher pickles.) Into the bottom of the bucket I place a rack covered in a square of plastic cheese mat (cheap sushi mats work, too). On top of all of this I place the wheel of cheese to age, flipping weekly, leaving the lid cracked about 1 inch for a little air flow. The cheese itself provides the needed humidity and the basement floor keeps the temperature moderated. As the cheese ages, the bucket will develop it’s own little micro-ecosystem of bacterias and molds. Each bacteria and mold has a a preferred condition on and in the cheese. Depending on the amount of moisture, salt, acid and oxygen, the ecosystem will evolve as the cheese ages. After one or two weeks, holes are poked through the cheese with a skewer to allow air into the interior, which lets the mold vein on the inside. The cheese will start out a lovely shade of blue, then turn into a moldy, stinky monster. Once a month, take the cheese out of the cave and carefully scrape off the exterior mold layer. The cheese will go from robins egg blue to polka-dotted blue/white/gray to reddish/gray/white. After 2 month, despite the moldy exterior, you’ll have a mild blue cheese. Each month of aging will add more flavor to the cheese.

Think of blue cheese as a glorious science experiment. You’ll be amazed at how milk can transform into an incredibly flavorful cheese. Stinky good, I say!

(1) Wikipedia Blue Cheese