I've olny had a bad batch of mold once. I bought a box of '98 Punch RS 12s and when the arrived the had a beautiful case of plume (also tasted and smoked amazing). Due to this I smoked them very sparingly. I had them buried at the bottom of the cooler for a couple years when I found them again only to discover they the entire box was overtakes with mold. It was a very sad day when they had to go into the trash. As a result I went back to a wineador and haven't had any problems.