What is the shelf life of chestnut flour? Thanks, everyone. ;o)

I noticed black layer on top of the chesnut flour in a few days of keeping in the jar. I removed and strained it thinking maybe it got bugs... but nothing and the same thing happened again. The flour looks fine and dry. No mould or anything but it has black layer again on the top like the black particle of the flour are coming up. Anybody knows what is happening???

I keep my chestnut flour in the fridge and it hasn't gone bad in over a year. But you must absolutely buy it from a trusted source, otherwise you could be buying flour that has already gone off.

Unless you freeze it, chestnut flour should be used very soon after it is produced. Figure the chestnuts are harvested in September or October--I’d try to use it up before the following spring.

I also keep it, as well as most of my other nut flours, in the freezer.

What a lot of contradictory info on the internet! But personally I've kept it in the freezer for more than a year.

nut flours can go rancid pretty quickly if they are kept at high temp's or in direct sunlight. It should be dated on the bag, but if you taste it with a dip of your finger you'll notice right away if it isn't fresh. It will taste like a nut gone bad or just plain old.