With the fireplace not only serving as a functional heat source but also as added decor to a home, black stains caused by soot can be an eyesore. The stains can leave an ominous black smudge on brick, but fortunately it isn't as permanent as it looks. There are several very effective ways to remove soot from brick.
Press play dough or some other kind of children's moulding dough onto the soot and simply lift it away. If the stain is small, this is probably the easiest method. Be sure to use light-coloured dough and be careful if the brick is older not to pull away parts of the brick and damage the fireplace.
Toss salt into an already burning fire. A few teaspoons of salt will help the fire turn the soot stains to smoke and move them off the brick and right up the chimney.
Mix together Dawn dish soap and hot water. Apply this to the stain and allow it to sit for a minute or two. Use a scrub brush to remove the stain, rinse and allow it to dry. Repeat if necessary.
Combine 28.4gr. of salt, 29.6ml. of detergent and water until you have a paste. Apply this to the stained area and remove with a stiff wire brush when it is dry.
You can purchase several cleaners on the market that may do the same thing. Brick Anew, Quick 'n Brite and any oven cleaner will help to remove a soot stain if you don't mind the chemicals. Be sure to read and follow the instructions carefully for each product.
It may be a good idea to test the durability of the brick before engaging in vigorous scrubbing. Older brick may crumble, so try your chosen method on a small area and see how it holds up. You may need to adjust your cleaning method according to the stability of the brick so as not to damage your fireplace.