Generally, the darker the smoke the more impurities in the smoke. Burn grass or wood and you get almost all the fuel burned “cleaned” you get white smoke. read more
Burn grass or wood and you get almost all the fuel burned “cleaned” you get white smoke. Add in any man made products (hydrocarbons) and you don't get complete combustion of the fuel and impurities darken the smoke. read more
Brownish smoke is the beginning of structure fire-the wood is getting hot enough to combust, and the brownish smoke is a sign that it's starting to burn. Darker grey is a sign that it's seriously burning. read more