Hello!
I'm a professional pastry maker (pâtissière, I can never figure out the exact translation in English) and also a gluten free baker at home so I have a lot of experience with using flours past the best before date (I have about 20 different flours at all time, not enough room in my freezer so I only freeze a couple of flours which I know are extra sensitive and keep the rest in my pantry). It really depends a lot on the storage environment, a dry cool and dark place like yours is the best. It also really depends how it was milled. A flour that got too hot when it was milled will go stale much faster, I'm not sure why but I think it somewhat damages the natural oils in the flour which go rancid. I've seen flours stay good as new years after the best by date, and I've seen flours go bad a few month after the best by date.... or months before! I hate wasting (they are so expensive!) so I keep those for dusting loaves, rolling naans and other flatbreads... the stale taste disappears when they're toasted brown.
As for the rising, it does seem like the protein in the bread might deteriorate overtime, leading to less gluten being available which can lead to poor rising.
If in doubt, just don't bake bread with an old flour and save it for cakes, since the reason why we add flour last is to develop as little gluten as possible and avoid a tough crumb.
Hope that helps :)
Oriane from France

• Reply