Whether it was an honest accident or not so much, Beer stains happen. Colorization is caused by two different chemical reactions.
The first one is a chemical process that attaches the amino acids to the sugars in the beer, and the second one prompting those sugars to break down.
These processes largely impact the beers flavor as well. So naturally the best way to get out beer stains would be to try and reverse the processes that created the color.
We have put together 7 easy steps on how to remove beer stains from a rug. Just follow the instructions.
Also, at any other beverage accident, make sure to get help from these stain removal guide, such as Red wine, White wine, Milk, Tea, and Coffee.