Just bought a bag of Traeger the same day from Home Depot.
Seem dry enough. Not much powder either.
I've never done it, but some guys microwave the pellets or put them in the oven to make sure that they are dry. Sounds like it may stink like hell though. I was going to dry some in my smoker, and store in an airtight container but haven't done it.
I can't prove it for sure, but it seems like I get a ton of moisture in my electric smoker with pellets compared to wood chips. People claim that pellets absorb moisture more than chips and chunks.
I'm in the PNWet, and it's really only dry in July and August so that might have something to do with it too.
