The walnuts are sent through a machine several times that cracks the shells and separates the shells and meats.
Walnut harvest is from September to November in California. Last week, I was invited by the California Walnut Commission to see the walnut harvest at a farm near Gustine, CA. We visited a walnut farmer and saw the process of harvesting the walnuts and preparing them for consumption, and then we visited a processing plant where we saw the walnuts sorted, cracked, and packaged. I got to eat many different dishes that incorporated walnuts in them and learned many walnut facts!
According to Frank Rebelo at Rebelo Orchards, 99% of walnuts in the US come from California. Walnuts originated in Persia, and are the oldest known tree food, dating back to 7000 BC. They were brought to California in the 1700's by Franciscan monks. Walnut trees can produce for up to 35 years. Walnuts are perishable; once the shell is cracked, they should be eaten immediately or the oils go rancid. Uncracked walnuts can keep for up to 2 years if stored in a cool, dry place. Cracked walnuts should be kept in an air-tight container or in the freezer.
Ron Martella at the Grower Direct Nut Company said that this year's walnut harvest has been 400,000 tons so far! Here's a really neat video showing the tree-shaking machine that harvests the walnuts:
Walnuts have the most alpha-linolenic acid content of any nut by a wide margin. Dr. Michael Roizen recommends eating 12 walnut halves per day in order to cut your heart disease risk in half.
How do you like your walnuts? I love them candied and tossed in a salad with some blue cheese, pureed with pumpkin in ravioli, and in muhammara, a delicious red pepper and walnut dip.
Recipe: Green Salad with Walnut Oil, Celery and Radishes
Loving: Roasted Walnut Oil
Nocino and Vin de Noix: Making Green Walnut Liqueur
Recipe: Apple Walnut Bread Pudding
Recipe: Spinach, Peach and Walnut Salad
More Walnut Recipes - from the Walnut Board
(Images: Kathryn Hill)