1) their species
2) their age or maturity
3) presence of larvae in them
4) storage methods
Truffle experts recommend proper storage methods to ensure the freshness of these mushrooms for at least two weeks after harvest. If proper storage conditions are met, they can remain fresh for many months.
There are a number of arguments on whether to clean or not to clean truffles before storage. Most culinary masters agree that truffles should not be cleaned until the day you are ready to cook or to use them. According to these culinary masters, truffles must be wrapped individually in paper towels to maintain their freshness. They also recommend the use of air tight containers for storage. These containers may be in the form of jars with tight covers or Ziplock bags.
Truffles that will not be used in a couple or more days after harvest can be kept frozen up to six months. Before placing them in the freezer, wrap them in plastic sheets, then in foil and then place them in a closed container. You can also immerse them in a bowl of olive oil prior to the wrapping procedure. This will enhance the aroma of the truffles and generate truffle oil in the process.
Truffles can also be preserved by storing them in rice. Rice grains keep the natural moisture of truffles. They absorb the extra moisture truffles emit to avoid quick decay. After some time, these rice grains will be truffle-flavored. Then, they can be cooked as a separate dish.
Do you need a step-by-step guideline on storing your truffles? Read this detailed infographic from Susan Alexander Truffles.