How do you get rid of coffee stains in mug?

1. Rinse the mug with cold water as soon as possible. This will help to prevent the stain from setting.

2. Fill the mug with a mixture of equal parts white vinegar and baking soda. Let it sit for at least 30 minutes, or overnight if the stain is particularly stubborn.

3. Scrub the mug with a sponge or dishcloth. Be sure to get into all the nooks and crannies.

4. Rinse the mug thoroughly with hot water.

5. If the stain persists, repeat steps 2-4.

Here are some additional tips for removing coffee stains from mugs:

* Use a soft sponge or cloth to avoid scratching the mug.

* Be careful not to use too much baking soda, as it can be abrasive.

* If the mug is dishwasher-safe, you can also put it in the dishwasher with a cup of white vinegar.

* You can also try using a commercial coffee stain remover. Be sure to follow the directions on the product label.