If you've ever wondered what gives blue cheese its funk, we've got answers.
Blue cheese.
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Though it might be a regular topping of choice on your favorite salad or burger, chances are you don’t 100% understand the complicated biology of blue cheese. We’re here to unearth blue cheese from its funky shroud of mystery—and maybe give you some fun facts to spout to friends over wine and a classy cheese board.

What is that blue mold, really?

The short answer: Penicillium Roqueforti and Penicillium Glaucum. The long answer: They’re safe-to-eat blue molds that thrive in very specific ranges of temperature and acidity. It’s alive and needs food, air, and moisture to thrive, and cheese provides a great climate. Cheese makers typically poke needles into cheese early on in the process to make sure the mold gets adequate oxygen, and it's this process that gives blue cheese its typical veiny appearance.

So, what do these molds do?

See if you can throw around these fun words in casual conversation. First, let’s talk about proteolysis. These blue molds slowly break down proteins in the cheese as it ripens and ages, which is what makes blue cheese oh-so-creamy and smooth. Then, we have lipolysis—i.e. when these friendly fungi break down the cheese’s fats, which is what gives it that signature tangy sharpness. The mold and the type of milk used is what gives these cheeses all of the distinctive flavors and textures you love.

But, isn’t mold bad for me?

The blue mold that makes up the cheeses isn't harmful because it never grows in conditions that allow it to produce toxins—but watch out for these warning signs. If your blue cheese starts smelling strongly of ammonia (think cleaning products) or acetone (like nail polish remover), it’s time to toss it. If it starts getting slimy and sticky, or turning pink or brown, that’s another indicator that it’s overstayed its welcome in your fridge.

OK, so, how do I use it?

This is the easy part—if you’re into blue cheese, it’s as versatile as you want it to be. Throw it on top of a pizza. Crumble it on top of a salad. Give nachos a tangy twist. Bake it into a cheese puff. Make some fancy appetizers. The possibilities are endless.

I’m still not sold on the funk. What can I use instead?

Tangy feta cheese can be a good substitute if you’re looking to replace blue cheese in a recipe. Goat's milk cheeses, and depending on the recipe, a good sharp Cheddar can also make suitable subs if you’ve tried and can’t quite get over the "blue" flavor. We won’t hold it against you.