Stoked up the bed of coals this morning and threw on a log of pine, black birch, maple and red oak (mixed it up a little), let that get totally engulfed in flames, dialed the air down and went upstairs. I’ve been doing this or similar every morning since early November, never got black glass. When the flames were building up over the first 15 minutes I didn’t hear any sizzlers in there, and the wood has been cut/split/stacked for 1-2 years. Anyway, I’m upstairs cleaning the kitchen with Fantastic, and I can suddenly smell the wood stove in the basement over the Fantastic smell. So I’m thinking “that’s a strong smell to overpower the cleaning products”. So, I go downstairs and the glass is almost totally black. Very strange. So, I assume something is up with the draft. I went up on the roof and gave the chimney a good sweep. At the clean out nothing but a pile of powdery black stuff. Strange, not sure what’s up. I’ve since cleaned the glass and will see what happens with a new fire tonight. I’ve got 35 feet of chimney, it’s 38 degrees out, burning an Englander 30NC.