Wipe or wash the mushrooms, remove or trim off the stems, then peel them and sprinkle with salt, and pack carefully into clean glass jars, without adding any water. Adjust the rubber ring and screw down the lids slightly, then put into steriliser or saucepan with false bottom; fill up with water to reach to about an inch from the necks of jars, then bring gradually to boiling point and boil for one hour, during which time it will be found that they have shrivelled up and drawn their own juice. Remove the jars from the water, and fill up one from another, then return to the steriliser, and allow to boil gently for another hour. When done screw down the lids tightly in the case of screw-top jars, or clamp down the spring of spring-top jars.
Mushrooms may also be dried instead of sterilised by being put in a cool oven or outside in the shade on sheets of white paper and left until dry and shrivelled up, then stored in paper bags. When being used they should be soaked beforehand, preferably in gravy.