We've enjoyed chestnuts ever since a friend with a tree let us gather some from his yard, and every year we enjoy them more and more. But we're still figuring out some of the details of how best to store and prepare chestnuts for roasting (and boiling, although we mostly prefer them roasted. We also eat a raw chestnut now and then, but we mostly roast them.) We did an experiment this evening with different methods of scoring chestnuts, and we also compared roasted chestnuts that had been in refrigeration for a few weeks to roasted chestnuts that were just collected.
We definitely preferred the cured chestnuts to the freshly harvested. Chestnuts sweeten with proper storage (in the refrigerator but protected from drying out too much), and they also shrink away from the shell just a little. The chestnuts that we've had curing for the longest have been in the fridge for about a month, and we didn't notice any signs of any of them going bad. (There's always a small percentage that have imperfections when we collect them, but no more had started to go bad.) We can't remember exactly, but we think we kept them in the fridge for 2-3 months the last time we had a good crop (2019?). That's probably close to the limit of how long they'll keep in the fridge. It seems the flavor continues to improve at least through about 3 weeks, although that may vary some with the temperature and humidity of your refrigerator. For longer term storage, we roast them just like we would to eat them and then freeze them.
In order to prevent the nuts from exploding in the oven when we roast them and in order to facilitate peeling the shell off afterwards, we score the shells. We tried a couple new-to-us scoring methods today that seemed to work better than using a knife like we used to do. One method was to make a hole in the shell with a small nail and a hammer. That seemed to be enough to keep the steam from exploding the chestnuts in the oven, and we were able to crack most of the chestnuts by hand after they were roasted, and the remainder cracked easily enough with a regular hand held nut cracker (like for walnuts, hazelnuts, etc.) We only tried that with chestnuts that had been in the fridge for a few weeks, though, and we're not sure if it would work with fresh chestnuts, but it was a very easy method and worked very well with the nuts we roasted today. The other method we tried was to use scissors. That also worked very well, and unlike the nail and hammer, it's a method we've seen other people recommend as well.
