I'm getting mine from a store in Arizona that sells native species, called Desert Survivors. (
http://www.desertsurvivors.org)
As for gathering and processing, I got this information from the book 'From I'Itoi's garden: Tohono O'Odham Food Traditions.'
In the Sonoran Desert, the acorns are ready to be picked from early July through August, depending on the weather (this is the rainy season for this area).
To Pick:
If there is too much rain, acorns may be too wet to pick, so you may need to wait until they have dried a little before picking.
Ground Method: kneel or sit on the ground and brush away the surrounding leaves and dirk with hands or a stick. Wear gloves; the leaves are often pointy. Gather the nuts you find.
Tree Method: place a blanket or canvas under the tree and hit the branches with a stick. Nuts will fall off onto the blanket and can be gathered that way.
To prepare to eat:
Remove any caps on the nuts, if present. You can wash to remove dirt, but it's up to you.
You can crack the thin shell around the acorn with your teeth by biting around the center of the nut. The shell will pop in half. There is a fuzzy brown coating on the inside of the shell, this is edible but can be scraped off with a fingernail, if preferred.
If a nut is black, don't eat it. That's an old one which may have worms.
Storage:
They must be completely dry before storing. If they are damp from rain or washing, spread them out in the sun to dry before storing them.
They will keep for at least a season. They can be stored in jars, cans, plastic bags, or sacks, if kept in a dry, dark place. DO NOT store them in the refrigerator. They will get moist and rot inside.
From what I understand, Emory oaks have the least tannins of all the acorns and are the only ones that don't require any processing to leach tannins. They are a desert tree, with medium
water needs and living in alkaline soil, at least the variety I'll be getting at Desert Survivors. I would imagine it might have problems with temperatures too far below freezing for too long. The following page tells a little bit about them, including the ranges where they grow:
http://www.slowfoodusa.org/ark-item/emory-oak-bellota-acorns
