The walnuts must be pickled green, before any shell has formed.
The shell forms from the bud end, so test with a needle.
If you are lucky and the shell has not started to form yet, take
your bucket of nuts off home, and wash and sort out any damaged
ones, and dispose of leaves.
Then prick all the nuts well with a needle, and drop into strong
brine. Leave for a week, stiring every day, and then change the
brine and repeat.
At the end of two weeks in salt water, rinse the nuts well, and
put them out in the sun to dry for a day. At the end of this they
will be a shiny black. Load into steralised jars, and cover in
boiling vinegar flavored with allspice, mace, black peppercorns
and cloves. Leave at least 6 weeks before eating.