if the glass in the door blackens

The trick is to dry the glass in the first couple of minutes after lighting the fire.

When lighting the fire: 

• take off the rear door
• open the front door
• check that the chimney’s valve is in the open position
• when the flames are lively, slide the rear door back into place
• when the flames run through the oven chamber, close the front door

About a minute after you close the front door, condensation can form on the glass which is caused by the difference in temperature of the hot fire and the cold door.

What you can do:

• open the door and wipe the glass dry with a paper towel
• close the door
• repeat this until the glass remains dry

This will help prevent soot from sticking to the glass
​However if the glass continues to fog during cooking (depending on humidity in food), you can just wipe it with paper towel.

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