Ancient and worldly, walnuts have been treasured for millennia as a source of sustenance. One of the oldest nuts cultivated by man, walnuts originated in Persia and were traded along the Silk Road, spreading in popularity in Asia, the Middle East and then Europe. Walnuts were introduced to California by the Franciscans in the 1700s, where they flourished in the Mediterranean-like climate. Today Californian walnuts grow primarily in the Central Valley where the mild climate and rich soils provide perfect growing conditions.
Not to rest on their historic laurels, by today’s standards walnuts are also considered to be a superfood, due to their exceptional nutritional value. High in protein, vitamins, minerals, packed with antioxidants and omega-3 fatty acids, walnuts are a rich source of energy. They also taste great, adding subtle sweetness, smooth buttery flavor and crunchy texture to savory and sweet recipes.
Last week I had the opportunity to tour Diamond Nuts near Sacramento, California. For all of my cooking and writing about nuts – not to mention eating – I had never seen how a nut is harvested and processed. As the season and location would have it, it was prime walnut harvesting season in the Central Valley.
When the walnuts are ready for harvest a special hydraulic driven shaker grabs the trunk of the walnut tree and shakes it for about 15 seconds, resulting in a shower of walnuts to the ground. Imagine a 30-foot tree doing the shimmy and you get the picture.
The carpet of fallen nuts are blown by a sweeper (similar to a large leaf blower) into neat piles down the centers of each orchard alley.
The nuts are transported by trucks to the processing plant, where they are sorted. hulled, and washed.
Then they are left to dry in enormous vats at 105°F to dry out the in-shell walnuts to an 8% moisture level. Picture a walnut sauna.
From there the freshly transformed and spiffed up walnuts are transported to the packaging facility where the powers-that-be decide to halve, chop, dice, and grind them, not to mention salt and sweeten.
All wrapped up and boxed, they are shipped off to stores and the world for purchase and consumption, winding up in our kitchens – which is where we come in. I cook a lot with walnuts, especially during the holiday season, and here are a few of my favorites:
Disclosure: My visit and tour were hosted by Diamond Walnuts with no obligation to write this post. All opinions are entirely my own.