How to clean tannin stains from mugs
Us Brits do like a good cuppa. What isn't so nice are the brown stains that can build up in your favourite mug over time. Some people may choose to bleach the stain, but that may not get rid of the the tannin build up; it will bleach it, making it harder to see if the build up has truly been removed. You could try a scoring pad, but that can be fiddly and time consuming.
There's a very easy way to eliminate the problem, restoring your cups and mugs to their former glory, so you won't be ashamed of giving your guests a cup of Rosie Lee in it.
Simply dissolve Soda Crystals in hot water and leave it at least half an hour. Then simply wipe round with a dish cloth or brush. You'll be surprised at the difference.