Wash crayfish until clean, boil in salted water with dill, and let them cool. Clean the tails and press thoroughly in a napkin to remove any excess moisture. Place in a jar and pour on crayfish butter.
Or dry them slowly in the oven and, before using, soak them in water for several hours.
Or place the boiled and cooled crayfish tails in a jar and cover with cooled vinegar that has been boiled with spices, but no sugar.
In general, crayfish tails cannot be kept for long. Wash crayfish backs, that is the shells, as clean as possible, dry them, store them in a jar, and stuff them for serving. Also wash the shells left from the small claws and tails. Dry and pound them and store in a jar. Use this powder to prepare crayfish butter as indicated in the next recipe because crayfish butter may be prepared from either fresh or dried shells.