Pickled walnuts used in recipes, commonly cooked in beef dishes. 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. 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
Juglans californica "J. californica" grows in riparian woodlands, either in single species stands or mixed with California's oaks ("Quercus" spp.) and cottonwoods ("Populus fremontii"). "Juglans californica" can be either a large shrub with 1–5 trunks, or a small, single-trunked tree. The main trunk can fork close to the ground, making it look like two trees that have grown together, then diverged. It has thick bark, deeply channeled or furrowed at maturity. It has large, pinnately compound leaves with 11–19 lanceolate leaflets with toothed margins and no hair in the vein angles. It has a small hard nut in a shallowly grooved, thick