If you keep most cheeses too long, they will eventually mould. Sometimes you can cut off the mould and still eat the cheese, but you can avoid the problem a little longer with some vinegar and a paper towel.
Photo by Antti T. Nissinen
You'd think this would make your cheese taste like vinegar, but it doesn't. Just use enough to keep the paper towel damp but not wet. Some versions of this tip I've read say use apple cider vinegar or cheaper, white vinegar. I tried both and tasted no vinegar. Just give it a minute or two to air out before you eat it.