Ricomorelo: doing so (or any soaking for a long period of time - i.e., > 5 min) will ruin their delicate nutty flavor. The best way to conserve them is dehydration - this process also removes the undesirable dwellers (insects) and the toxins naturally occurring in the fresh morels. Dehydrating them also concentrates their flavor, which truly comes to light when they are revived in milk or cream. Morels can be kept fresh a max of 2 weeks in a cool dry place. Also rules #1: never eat morel raw and never fry them.