2 Year Old Grains - still good?

I'm doubting these grains are even usable, but...I'm starting to help our local LHBS owner get a brewing community up and running and while I was in the store, he said, "Yeah, those bags of grain have been there for like 2 years. Can you use them?" I said that I didn't think they'd be any good (they're 1# bags of Vienna 6 Row and Biscuit and such)....but, are they? Could I throw them in with something? Are they display only at this point?

Taste them- the only true test.

find some cheesy hops and some old belgian yeast, build up a starter with the lid off and make a funky ass belgian beer.