Once the walnuts have done their briney stint for a couple of weeks, drain them and spread them out onto a tray lined with absorbent paper and leave for a couple of days to dry out. They will turn black. This is normal. They will also stain anything they come into contact with. Including your hands - in fact you will look as though you have been on a 100 a day nicotine addiction for the last 10 years if you handle them without gloves.
Once they blackened they are ready to be pickled.
In a large saucepan (large enough to accommodate all the walnuts) bring to the boil the following pickling liquor:
1 litre of malt vinegar, or a red wine vinegar. Use something with some colour to keep the dark colour of the walnuts.
to the vinegar add:
500g of sugar
1 teaspoon of allspice
1 teaspoon of cloves
1 large cinnamon stick
2 cms of grated fresh ginger
One the mixture starts to boil, add the walnuts and leave to simmer for 15 minutes or until the smell of vinegar makes your eyes bleed. (that may just be me though so don't worry too much).
Bottle up into clean jars while still hot. Bottling while the vinegary syrup is hot negate the need for excessive sterilising of jars.
These will keep for years, and are apparently very good with cheese. I have tried them but was not overly struck on the flavour, but I do know someone who really likes them so that's their presents sorted for the next few Christmases.