I was stunned by the difference in taste between Old Fitz 1849 and Four Roses Yellow Label..... It made me realize you need a fresh glass for each bourbon! now as I sit before the tube... I have a glass of Britta Filtered water and I douched out my whiskey glass and drank it down. I reckon that purified my glass.... did I just invent something? before I was using new glasses. Now I am washing the glass out with drinking water to get it ready for the next pour. Granted, I normally don't have more than two, but for some reason today demands more.... am curious how you all deal with glasses when sampling a variety of bourbons......?