T Nation

Forgive my ignorance

Can protein powder expire? Is it best if used before a certain amount of time passes? Here’s me situation: to save money, I really prefer to prefer to buy in bulk - I would like to buy up to a year’s supply at a time. is this feasible?

It may depend. It certainly can in some cases.
I had some CFM whey to which an enzyme had
been added to speed digestion – it turned
nasty after a number of months (however, that
may have been due to the enzyme.)

If unopened, it should be okay…I won a year’s supply of protein for this contest that I entered.
One thing to note, though - I always believe that it’s good to rotate which protein you use. Each company’s protein will tend to have a specific ratio of whey fractions, casein, and other proteins (in a perfect world where every company’s label matches the contents). I think that it may be a good idea to switch brands every now and again in an effort to widen the spectrum of aminos you’re ingesting. Something to think about, anyhow. Good luck.

Protein powder as with other food items can oxidize when exposed to air. It is this oxidation that causes it to expire or go bad. If sealed in air tight container, should last pretty good but after opening and exposing to air, if not going to consume or use in a timely fashion, it is best to dump in a big ziplock style bag where you can squeeze all the air out and reseal air tight. The big 10 pound tubs are air tight but still expose the powder to a lot of air after half empty.