It seems almond meal (sometimes called almond flour) has burst onto the culinary scene in the wake of the high-protein, gluten-free craze due to its ability to at least partially replace wheat flour without adding carbohydrates or gluten. Since the meal is ground from whole almonds, it can go rancid if not stored properly.
Because of its high oil content, almond meal should ideally be stored unopened in the freezer for the longest shelf life. Oils begin to go rancid when exposed to oxygen. Once opened, store the meal in an airtight container and keep it in the freezer. Whole almonds will keep in the freezer for up to 2 years, but because almond meal is ground, more of the nut is exposed to oxygen. This slightly lessens its freezer shelf life. Freezing the meal also helps prevent the growth of "pantry pests," bugs that feed and multiply in packaged nut products.
Tips
When storing almond meal in the freezer, allow it to come to room temperature before using in recipes to prevent clumping.
If freezer space is at capacity or you just want immediate access to unfrozen meal, opt for storing it in an unopened or airtight container in the coldest part of the refrigerator. Airtight containers include Mason jars and zipper-locking storage or freezer bags. Almond meal stays fresh in the refrigerator for up to 6 months.
Almond meal stored in the pantry has a shorter shelf life than when stored in the refrigerator or freezer. Warmer temperatures accelerate the degradation of the fat in the nuts and the oils turn rancid faster. Again, use an airtight container and store the meal in the pantry for up to a few months.