Pickled walnuts are made from the fruit of both common walnut tree varieties:
Juglans regia, the Persian, royal, English or common walnut, and
Juglans nigra, the black or American walnut.[
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The first stage is to pick the walnuts whilst they are still green and before the shells have set. Most recipes say that late June is about the best time to pick them. The soft walnuts are then soaked in
brine (salt water) for at least ten days. The walnuts are then drained and left to dry in the air. Soaking the walnuts in brine causes a chemical reaction to take place and the walnuts turn dark brown to black in colour when exposed to sunlight. The now-black walnuts are then placed into jars and a
pickling solution poured over them. This can vary from a straightforward pickling
vinegar to a solution containing spices and sugar. The walnuts are sealed and then left in the jars for anywhere between five days and eight weeks depending on which recipe is followed
