Storing & preserving chestnuts & chestnut flour

Anyone got a tips for long term storing/preserving of chestnuts & chestnut flour?

Chestnuts make a great flour but its a bit let down by its short lifespan. I'm looking to store a lot, so freezing is too limited and costly, so was wondering if anyone has any experience with vacuum sealing the chestnuts and/or chestnut flour to prolong it's shelflife? Particularly using a vacuum sealer which removes the air (not just simply seals the bag). I'm wondering if it would be possible to extend the shelf life of chestnuts & chestnut flour to as potentially long as a year with this method?

Any one got any experience of preserving chestnuts and flour this way, or even other foods for that matter? How long can it extend the shelflife of foods for?

There’s a good book that covers this by Martin Crawford called how to grow your own nuts.

I developed a method for processing and preserving acorns that I would guess could work with chestnuts also.  Both nuts are starchy and moist rather than oily, and relatively perishable compared to other nuts.  Essentially I clip each nut in half with a good pair of heavy hand pruners, and then dry the cut halves in the sun until hard and dry.  For my own use and longest storage I try to heat them by batches to 150 degrees or so in my solar oven, which should kill any worms and their eggs (also a big problem in acorns).  Another advantage of this is that the nuts shrink relative to the shells and are then relatively easy to separate, usually by cracking them up in a nutcracker of some sort (which would never work with the fresh nuts, they are too pliable) and then picking the nuts out from among the shells by hand.  These dry nut pieces, whether with the shells or without, can be stored for months in bins or jars or some such away from moisture and heat.  I would say they should last at least a year, although the oils in them will gradually go rancid.  More airtight storage or freezing might hinder this.