The ember can be used in a better firebrand recipe to produce a longer lasting firebrand.
It takes 5 sticks instead of 2, and the ember is not consumed on use. Instead it is returned with 1q lowered in a random quality. The ember can be reused until it hits 0q in any category, after which it is destroyed. The recipe is also faster to use with less stamina consumed.
Just something to have when the firebrand struggle is too much to handle.