On Saturday, January 18, 2014 10:47:16 AM UTC-6, woodchucker wrote:

Try cleaning with oxalic acid before you stain.

It will clean the wood and remove anything left.

Jeff

Do you have personal experience using that method?

You realize of course, that when you bleach out the stain with the acid, it won't discriminate between the stained areas and the unstained areas, right? So cleaning the area will lighten that one area on the entire on the entire project. This will be like using full strength Clorox to treat a spot on a black dress shirt.

The original poster should post more info about size and appearance of the stain, what kind of oak it is, and how the stain has been treated to this point before expecting an intelligent answer.

It is important to note that the OP never said there was any kind of stain to treat or deal with. For all we know, the beer was spilled and immediately wiped off and you can't even tell where the spill was.

Robert