slightly under ripe fruit
Peel Off Skins
The easiest way is to pinch the tops of the skin and squeeze out tomatillo
Wash off sticky coating
Pierce with a clean needle to prevent bursting. Place in a non reactive pot and cover with water. Lightly boil for 5 minutes and then place into clean hot jars with a slotted spoon. Cover with the boiled water leaving a 1/2" head space like I did on the right. If you run out of room, smoosh them down like I did on the left. Less attractive and voids the piercing, but less wasteful too. Tomatillos are naturally high in acid so no need to add more. Submerge jars in hot water bath for 40 minutes for quarts and 35 minutes for pints or 10 minutes in a steam canner.
adapted from the Joy of Cooking