White and black truffles are some of the most costly ingredients in the world. But what exactly are truffles, anyway? And why is the price tag so steep? Get those answers and more in this deep look into the tiny coveted underground mushrooms.

Several years ago I enjoyed a fancy multi-course meal with one standout dish I still dream about: truffle risotto. It was my first experience with truffles (and legit risotto, for that matter), and I savored every last bite. Fast forward to a couple of weeks ago, and I accomplished another culinary goal by cooking with my first-ever black truffle in celebration of the annual Black Truffle Festival. The virtual session taught me how to make the most amazing truffle pasta (more on that later). After indulging in one of the best meals I’ve ever made at home, I realized I still didn’t know much about these delightful truffle mushrooms. And since truffles cost so much, I wanted to know the best way to store them so I wouldn’t let any go to waste. Here’s what I found out so you’ll know what to do if you are lucky enough to get your hands on a fresh truffle.

What Is a Truffle?

A truffle (not to be confused with the chocolate treat) is a type of fungi that is found on the roots of trees. Unlike the common mushroom varieties, truffles grow entirely underground on the roots of trees. According to Sabrina Notarnicola, vice president of marketing at Urbani Truffles, they are “primarily found in Italy, they can be found in similar Mediterranean climates around the world.” There are several species of truffles but the most common edible varieties are black truffles (Tuber melanosporum) or white truffles (Tuber mangnatum). Europe produces the most valuable truffles (though there are truffle farms in North America and Australia).

What Do Truffles Taste Like?

Unless you’ve had them, it’s hard to describe what truffles taste like. Black truffles feature an earthy aroma and taste. White truffles have a more pungent smell and flavor.

Why Are Truffles So Expensive?

When buying truffles, they can go for hundreds (even thousands!) of dollars per pound. Notarnicola says truffles grow best in moist environments and after a rain, large truffles can appear overnight. So what’s the deal with truffle cost? “Truffles have a high price point because nobody has been able to cultivate them,” Notarnicola says. “They are only found in the wild and are very seasonal.” Technically you can find different varieties of truffles at all times of the year depending on the growing location (i.e. black summer truffle, black winter truffle, etc.). You’ll find white truffles mostly in fall and winter, with their peak season in November and December.

How to Store Truffles?

So you got a black truffle, but what’s the best way to keep it fresh? Notarnicola says truffles (black or white) are best stored refrigerated, individually wrapped in a clean paper towel, and inside of an airtight container. You might see some guides saying to store in rice (the dry rice grains wick the moisture from the truffles), but don’t do this unless you are trying to infuse the truffle flavor into the rice. “Truffles are highly perishable, so by the time a truffle reaches a customer, they can expect anywhere from 3 to 7 days of ripeness,” Notarnicola says. “Each truffle is different, so this is a variable.”

How to Use Truffles

Notarnicola says truffles can be served with almost anything. But the interesting thing about truffle mushrooms is that they lose their aroma as they’re warmed. White truffle is great sliced raw on top of risotto or steak. Use a truffle shaver ($15, Amazon) to achieve the signature thin cuts. For an easy truffle recipe to get started, you can make the delicious black truffle pasta I mentioned earlier. It’s got a simple creamy sauce made with truffle butter and Parmigiano Reggiano cheese that really brings out the truffle’s natural flavors.

If you’re not ready to shell out the money for a fresh truffle, you can get still get the aroma in popular products such as truffle oil ($23, Amazon), truffle salt ($18, Amazon), or the super trendy truffle hot sauce ($18, Truff). These truffle products use either a small amount of truffle or are infused with a natural essence of truffle to achieve the flavor profile, which keeps the cost low.