GOOD vs BAD There are many factors, but our first criteria for “good” centers around size, condition, and convenience. Size is straightforward: the bigger the better (more nut/less shell as the diameter increases). Condition includes environment, maturity, blemishes, and pests. Convenience includes collection location and requirements of storage and processing. Of the many, many varieties of oak (see USDA Field Guide to Native Oak Species of North America) we divide (for convenience) what we work with into “red” (pointy leaved) and “white” (smooth-lobed leaved) acorns. For processing and storage convenience (and higher oil ratios) we work mostly with red oak acorns, but we are happy to work with whites when we have time.
WHAT TO LOOK FOR The picture above shows green acorns. Early season acorns are green – they will turn more nut-brown as the season progresses and they dry.
Good acorns for gathering seem blemish-free, perhaps some mottling as they dry. The earliest acorns to drop are sometimes the tree’s cull (buggy ones) so check a few before you fill your basket. The rest of the harvest (in weeks to come) may be fine – but it is a good practice to crush a few acorns under any particular tree before filling your baskets. If the first few you find are very buggy – you may want to pass on gathering.
Bad acorns (examples below) include: acorn weevil holes (that’s an exit hole folks), cracks, bulging in odd ways, any black or yuck looking stuff), and a cap that is stuck on tight. Generally, the caps should be off, or come off easily when you try to remove them. A cap that is welded on usually indicates “inhabitants” – not good for human consumption (but still good for art/craft).
White oak acorns mature in one year, fall in autumn and sprout when they hit the ground. If you work quickly, you can process a newly sprouted acorn for eating. White acorns can be easier to shell, and all the processing steps are essentially the same. However, if you don’t work quickly to process or dry them – they either sprout too far (for our purposes) or spoil.
Red oak acorns take two years to mature, fall in autumn but do not sprout until the next spring. Their shell is a bit harder to crack, but we find them easier to dry and store. For this and a couple other reasons, we favor the red oak acorns so our travels, practices, recipes and workshops are all geared for that kind of nut.
We hand pick our harvests, doing a quick visual inspection before it goes in the basket. When we get the acorns home, we do a quick bath to knock the road dust off, and this bath serves as a “Float Test“ since those that float are often buggy and can be returned to the wildlife larder immediately.
IMPORTANT All acorns you gather will need to be dried before storage or further processing. If you leave your collection in the bag or bucket you gathered in – it can spoil within a day or two. Acorns can be dried on sheets in the sun, baking pans in the oven (below 110 degrees) or around the radiator or wood stove. Fully dried acorns in shell will store for years, but even if you intend to process for food immediately – a little drying time will make them easier to shell and sort. For further processing steps, please see guides at the top of our Resources page. Happy acorn hunting!