We have an 8 yr old walnut tree and this is the second year it has produced some nuts. We would like to try pickling some and have a recipe but it is not clear when the nuts should be picked. It refers to 'young, before the shell has formed'. Obviously it not possible to tell this from looking at the nut. We are assuming the whole thing is pickled, ie including the green outer casing.
I have a recipe but all it says is: Walnuts for pickling are available from late June and asks for "green walnuts"
"Prick each walnut with a skewer, discarding any in which the beginnings of a hard shell can be felt."
After scraping walnuts, let them stand in salt water for 2 or 3 weeks.
Scald twice quickly, so as not to soften them, and rub dry and put in jars.
Pour boiling vinegar over them and let them stand 2 weeks longer.
Then boil in very strong vinegar to every hundred walnuts 3 ounces each of mace, allspice, cloves, pepper, ginger, garlic, horseradish, and pour over walnuts and seal tightly.