Frequently Asked Questions About the Oregon Truffle
WHAT IS A TRUFFLE?
Truffles are among the world’s preeminent culinary delicacies. They are a form of mushroom that develops underground in symbiotic association with the roots of trees. Truffles are the “fruit” of these fungi.
HOW MANY TYPES OF TRUFFLES GROW IN OREGON? WHICH SPECIES ARE THEY?
Oregon has four native truffle species that are recognized for their culinary value and harvested in the wild. They include the Oregon Winter White Truffle (Tuber oregonense), the Oregon Spring White Truffle (Tuber gibbosum), the Oregon Black Truffle (Leucangium carthusianum), and the Oregon Brown Truffle (Kalapuya brunnea). The French Black, or Perigord truffle (Tuber melanosporum) has also been successfully cultivated and harvested by New World Truffieres in Oregon and numerous other spots in North America through planting orchards of inoculated host trees.
WHERE IN THE WORLD DO TRUFFLES GROW?
Truffles in the broad sense are found throughout the world, but the species recognized as culinary delicacies originate mainly in Europe, and in the Pacific Northwest.
Oregon happens by chance to have four native world-class culinary truffles, which made a truffle industry inevitable, as well as a lineage of truffle researchers at Oregon State University who have handed down their collections and knowledge to students and professors over the past century. Oregon also developed an industry around the harvest of other wild edible foods for chefs and restaurants, which provided a labor force and a market for truffles, which facilitated their introduction into the culinary world. Neither the knowledge base, nor the foraging industry exists to the same extent elsewhere. This effective head start for Oregon produced the Oregon Truffle Festival, New World Truffieres, and the North American Truffling Society well before truffle growers and harvesters in any other region outside of Europe began to coalesce into an industry. Finally, European truffles such as the French Perigord have been successfully cultivated and harvested in Oregon. This combination of an abundance of wild and cultivated culinary truffles exists nowhere else in the world.
HOW DO TRUFFLES GROW?
Truffles are the “fruit” of fungi that grow on the roots of host trees in a symbiotic relationship. The truffle fungus explores the soil for water and mineral nutrients, which it passes along to the tree. In exchange, the tree provides sugars produced through photosynthesis to the fungus. The tree and the fungus depend on one another, but there are many tree species that can serve as hosts for the truffles, and many fungi that can fulfill the same role for the tree.
WHEN DO THEY GROW IN OREGON? DOES IT DIFFER FOR VARIOUS SPECIES?
Using dogs to harvest truffles at peak ripeness, the harvest seasons for the various truffles found or grown in Oregon are as follows:
Oregon Winter White: January through April
Oregon Spring White: June-July
Oregon Black: October through July
Oregon Brown: September through January
French Black: December through April
HOW ARE TRUFFLES HARVESTED?
The highest quality truffles that make their way to market are harvested with the help of trained truffle dogs, who can identify ripe truffles by scent, while leaving unripe truffles to mature undisturbed in the ground. Unfortunately, some truffles are still harvested by raking, which indiscriminately produces mostly immature, unripe truffles. A truffle that is harvested before it reaches maturity will never properly ripen for culinary use.
WHY DO TRUFFLES COST SO MUCH?
Truffles’ rarity, seasonality and delicate handling required to transport them from soil to plate all account for their high prices. Prices for Oregon truffles have risen dramatically over the past five years with the introduction of trained truffle dogs, and Oregon truffles are now sold for as much as $800/lb, rivaling the famous French black truffles.
HOW SHOULD TRUFFLES BE USED AND STORED?
We recommend keeping truffles refrigerated in a sealed plastic container lined with a paper towel. The volume of the container should be mostly air, with a single layer of truffles at the bottom. To keep the truffles alive and healthy, open and air-out the container once per day. If the surfaces of the truffles become wet from condensation then they should be blotted dry, and the paper towel in the container should be replaced. If the truffles begin to sweat and grow soft, this is an indication that they are beginning to die and must be used immediately.
While you have your truffles in storage, it is a good idea to place eggs, cheese, butter, or any other foods containing some amount of fat into the container with them. The truffle aroma is fat soluble and will accumulate in any fatty substance in the vicinity. When you’re ready, you can serve them shaved fresh over eggs, pasta, ice cream, or nearly any other oily or fatty food.