Creosote is a sticky, ash-like byproduct that is formed when burning wood in your stove or fireplace. It can be tar-like and runny when hot or sticky and crusty when cooled. Creosote can build up on fireplace glass when your wood fuel has not properly combusted while burning. You can avoid the excess build-up of creosote by burning hotter, more efficient fires, which will keep your stove and fireplace chimney safer and cleaner. This will also make it easier for you to remove creosote from glass when cleaning.
Burn a hot fire to help remove creosote build-up from your fireplace glass before attempting to clean it. This can be achieved by adjusting the flue or air intake on your stove so the flames lap near the glass. Keep the glass door closed during this process.
Allow the stove or fireplace to completely cool so you may safely clean the glass and remove the ash. Put on rubber gloves before cleaning.
Scoop out a cup or two of thin ash from your fireplace or stove and place it into a container. Make sure there are no wood chunks or other debris--you want just the powdery ash.
Place unfolded newspapers or a plastic tarp underneath the glass door to avoid making a mess while cleaning. Take three large pieces of newspaper from the stack to use for cleaning and wad them up into a ball.
Dampen one of the newspaper balls with vinegar, squeezing out the excess. You will want the newspaper well-saturated but not dripping wet. Dip it into the ash to form a paste on the newspaper.
Rub the wet newspaper with the ash paste over the glass, scrubbing and using swirling motions while removing the sticky creosote from the glass. Discard the paper once it begins to deteriorate or becomes heavily soiled.
Repeat this cleaning method with the other two pieces of newspaper, using additional pieces if needed. The glass will still be smeared with ash, but you should be able to tell by the feel of the paper against the glass if there is any remaining stickiness.
Use clean paper towels or newspaper dampened in ammonia to remove the remaining ash. Check to be sure the creosote is completely removed. Dry the glass well.
Clean your glass twice weekly with the ash and vinegar solution to avoid heavier creosote build-up. Commercial glass cleaners are available specially made for cleaning fireplace or stove glass.
Never use ammonia near a hot fireplace or stove; it is combustible.