Growers of the

 "Périgord Black Truffle"

Storing Truffles

Truffles emit their aroma continually until it is totally exhausted; the rate accelerating on exposure to air. Either the strong pervasive truffle aroma vaporises and disappears or it permeates any other absorbent items kept in close proximity. At the same time the truffles will also dehydrate. Considerable care is thus required with their storage.

Following thorough cleaning to remove any adhering soil, truffles need to be kept in their own sealed containers. Any other suitable foodstuff, intended to be flavoured by the truffles, can be stored in the same containers. In restaurants where a number of truffles are constantly in use, these are kept in glass jars or on glass covered metal trays or wooden boards. Exposed truffles on display in shops and markets are sold or used the same day.

For short-term storage, no special measures are necessary but for longer storage periods, truffles need to be preserved by certain procedures.

Preserving Truffles

The truffle peridium (skin) forms a natural protection for the truffle gleba (flesh), and removing the skin and exposing the flesh will accelerate the truffle's deterioration. All truffles for culinary use should be thoroughly cleaned but kept intact and unpeeled until ready for use. If truffles are not going to be used immediately, their storage life can be extended to keep them fresh and preserve their flavour qualities by storing them short term in a fridge, and longer term in a freezer.

Chilling Truffles

Truffles can be refrigerated and kept fresh for up to two weeks. After thorough cleaning and drying, they are loosely placed inside a tightly closed, cry, airtight container, such as a mason glass jar, to exclude any moisture. The container is placed in the coldest part of the fridge (either next to the freezer compartment or, because cold air sinks, on the bottom shelf), with an optimum temperature of 2-4°C and relative humidity of 80-85%. Frost-free fridges are more efficient as they circulate the air to maintain even internal temperature distribution.

Freezing Truffles

wrapping the truffles tightly in metal foil before placing in the container can prevent frost from the internal moisture forming on the surface. Though freezing will cause the truffles to loose some of their texture, it also prevents dehydration and will thus allow the truffles to retain most of their aroma.

Frozen truffles are not thawed before using; the winter white, winter black, scorzone black and smooth black are shaved while still frozen, and the others cooked straight from the freezer, as they become spongy when thawed. Once any truffle is defrosted, it cannot be re-frozen without deterioration in quality, so it is used as early as possible.

Truffles in Rice

The best way of storing truffles to preserve their aroma is to emulate their natural underground habitat, soil, and completely cover them in a suitable substrate. Clean fine sand would do, but edible foodstuff is even better. The choice item to preserve truffles is uncooked rice grains. Truffles need their moisture to retain their aroma and should not be allowed to dry out. The rice grains will protect the natural moisture in the truffles, while preventing them from getting damp from excess moisture that could start decay.

During commercial transport, truffles are preserved after thorough cleaning, layered, spaced apart and completely covered in rice grains, in sealed metal trays or wooden crates and stored in refrigerated trucks. On delivery to restaurants, the containers are transferred to a refrigerated room, where they can be removed and used gradually.

For home storage, truffles are kept in an airtight, sealed stainless steel container large enough for all the truffles and the rice. A thick layer of rice is poured into the container and the truffles after cleaning are set a few centimetres apart from one another, and then covered up abundantly with more rice. The sealed container of cleaned truffles and rice is stored in a cool dry dark place, ideally at about 4°C. (3-5°C) in a refrigerator, when they will keep well in this near sterile environment for about three weeks.

Truffles stored in rice will not keep indefinitely; however, with prolonged storage, the truffles will not decay but will gradually dry out and the aroma will fade.

Stored together in sealed containers, the rice grains will be strongly scented by the intense aroma of the truffles but, while some of the truffle scent will be transferred to the rice grains, much of it will be intact. As the truffles are used, the truffle scented rice can be cooked as a separate dish. Any variety of rice is suitable for preserving truffles. Various local rice varieties are preferred in different countries: arborio rice in Italy , to be later made into a risotto dish, and bomba rice in Spain for a paella dish; camargue rice is used in France but the French do not have a traditional rice dish and so it is cooked as a popular Mediterranean pilaf dish.

Truffle Peelings and Truffle Paste

Such is the intensity of the truffle aroma, every scrap of it can be used, and it is fortunate indeed considering the effort involved in locating it and the cost. Both the peelings and little pieces too small for regular use can be made into a paste.

Spoilt Truffles

Fresh truffles should not be wrapped in plastic cling film or kept in plastic bags, as they then tend to become slimy and will rot very quickly. Even some haute cuisine chefs fail to preserve fresh truffles properly. Indeed many of them recommend wrapping truffles individually in absorbent (paper towels or similar) and storing them in plastic containers, changing the paper daily to prevent any build-up of moisture. This recommendation avoids condensation, but will cause the truffles to transfer their precious aroma to the absorbent paper, to be discarded with the paper each time it is changed, while the truffle aroma progressively diminishes. Some chefs even suggest not removing the traces of soil on the truffles before wrapping, thus trapping the dirt in with the storage.

When truffles begin to soften slightly, they have reached their highest ripening point and should be used immediately; after that they will start to deteriorate. If they have become mushy, show signs of sweating and releasing moisture, it is too late and they can no longer be consumed. Any whiff of ammonia indicates that the truffles are decomposing; they should be removed and discarded.

To avoid such waste, be conscious of the state of the truffles when acquired, and check them everyday for any changes in quality.