I've collected thousands of black walnuts over the last couple of months and have processed many of them. I have hundreds still remaining that have by now turned completely brown/black. Are they still viable to process, or have the hulls been on too long? I've read over and over about removing the hulls as quickly as possible after collecting, but I'm not sure what the affect is (taste?). These walnuts have been laying in a sandy spot in the yard, basically in a single layer. I don't see any evidence of mold.
Franklin County Ohio
While I cannot say for certain, I suspect the window for harvest has closed. Walnuts should be processed as quickly as possible to get the best product. I suspect that the nuts are discolored and have taken an off taste by now as well as the possibility of them going rancid or moldy on the inside from being left outside.