How Long Can You Store Black Walnuts?

Walnuts on a tree stump
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Are walnuts are still good after being left in the clean shell for a year? Say you have a bucket of walnuts in a storage room for a season. Here's how to make a decision: If they are stored in an outside shed exposed to freezing or high temperatures and potential insect and disease infestation, you'll want to toss the whole batch.

You will probably be OK if you have them stored in a secure climate-controlled environment or had them frozen after they dried. Storage conditions and the time the nuts spends in that environment is important. A quick test would be to crack one and test by taste and smell. Any off flavors will be immediately noticed and the nuts should be discarded.

Curing, Storage, and Shelling Information

Black walnuts will have a storage advantage when cured. Curing allows the walnut to develop deep flavor and will increase storage life. Curing black walnuts is an extra step that will take more time but will be worth the effort to preserve the nut-in-shell over time.

To cure the walnut - simply distribute the cleaned and hulled nuts in a layer of several nuts deep on cool, dry concrete, well-ventilated and shaded area for several weeks. The nut is ready to store when the kernel breaks crisply and with a snap.

When the curing process presents you with a tasty, crisp nut meat, store the cured, cleaned unshelled nuts under well-ventilated but cool conditions. The preferred storage temperature should be 60°F or less the relative humidity should be fairly high and around 70 percent. When walnut shells are stored under dry conditions, they tend to crack exposing the kernels to an environment conducive to spoilage. Use breathable cloth bags, burlap bags, wire baskets or any container that will allow for proper air circulation and discourage the development of rot bacteria and mold.

To make the process of shelling the nuts easier, you should moisten them. The moisture will help to keep the kernels intact and will reduce nut breakage. Soak the ​walnuts in hot (but not boiling) water for several hours. Some sources suggest an additional drain and repeat of the hot water soak. Keep the nuts moist until you're ready to crack the shells