Dust is definitely a possibility, I did just finish a bag for this smoke! I will start sifting in the future!Maybe dust from pellets. That is the only thing I can think of. Do you sift the pellets before adding to the hopper? Hopefully someone more knowledgeable will chime in.
There are many sources, but basically you just need a device that will sift. I eyeballed up the pellets and factored in what is the smallest size I’d want to keep. Then I assigned my shopping loving wife to the task. In a day or so she came back from one her favorite haunts, T. J. Maxx with a metallic sifter that was on sale for 5.99.Can you recommend a good sifter? I see too many on Amazon. Thanks