You'll see it called the "belch" on the forum, and my #1 really had a really big belch during seasoning. Almost like an eruption. And for the first few smokes, my #1 would belch at the beginning as it was heating up, right when it got to around 180 degrees as others have said. I learned very quickly not to stand there and stick my face over the hole enjoying the smell of the smoke! It comes from your wood being too dry, and sudden combustion. In the beginning I tried to use up some Weber wood chunks I had on hand, and I imagine they were pretty dry, even when new. Once I wrapped the bottom half of the chunk in foil, no more belch. I never thought I would buy "fancy" wood from the internet, but once I finally broke down and bought smokinlicious.com wood, I would never, ever go back to that wood you buy in home centers, big box, or hardware stores. I wish I had bought smokinlicious sooner. It is that good. And worth every penny. A small box of smokinlicious wood properly stored will last a very long time, because these smokers use such a small amount of wood.