Any residual soil covering the truffle provides a protective layer that conserves flavor and aroma, and even allows the truffle to continue its ripening.
Of course, upon cooking, the truffle should be thoroughly cleaned. Besides general rules of food hygiene, the truffle has to be cleaned because its outer peel (peridium) is never thrown away. Like with the inner mass (gleba) the truffle’s peel has flavor and aroma.
Proper Way To Clean Fresh Truffles
• For starters always wash your hands before handling truffles. Truffles quickly absorb outside smells
• Rinse the truffle under cold running water for about 30 seconds. Rinse only a few minutes before use.
(If you have a large sized truffle only rinse the portion of truffle you intend to use)
• Gently brush the truffle with an unused tooth-brush, nail-brush, or any other similar bristle and soft brush.
• Pat dry the truffle with white absorbent paper towel.
• Slice paper-thin, grind, or chop the truffle if ready to commence cooking or serve meal. Differently, immediately store away the truffle.