We’ve all been there. You get to the bar and order up a pint. And when it comes to you, instead of a pint full of amazing beer, it’s a dirty glass. There are tiny little bubbles on the walls of the glass, the head collapses within a matter of minutes, and it tastes like Band-Aids, solvent, or somehow like dirty socks. Gross. No one likes getting an unclean glass. The best defense against dirty glassware is to recognize the warning signs before you put it in your thirsty mouth.
What exactly is ‘beer clean’? Most simply, it is a glass that is completely washed of residue from other alcohols and/or liquids, previous use, and chemicals. Beer is a wonderfully fragile creature, and lingering residue will damage it or at least make it less pretty.
The correct cleaning process (for those places that hand wash glasses) goes like this, usually: 1. First sink, which should have a mechanical or manual brush, will scrub off any and all signs of previous use. This sink will probably have a non- or low-suds detergent and hot water. 2. Rinse. The second sink will likely be full of hot, clean water to wash away the detergent and anything left over from the brush cycle. 3. Sanitize. The third and final sink will hold Star San or similar sanitizing chemical diluted in hot water. For those bars that have an automated dish washing system, forget everything I just said. They have their own rules, which amount to heat kills everything.
Previous use, such as lipstick marks or fingerprints, is a very common and highly apparent indicator of not-beer-clean. Plus, it’s just plain icky. I know I don’t wanna see a giant thumb print belonging to someone else on my beer! However, it is possible that everything inside the glass is sparkly clean and ready to go and some lipstick was just particularly attached to the glass. That being said, don’t settle for drinking out of a lipstick-y glass. That is just lazy bartending/barbacking. You deserve better!
Residual liquids and/or other alcohols and/or bacteria are the culprit of another very common not-beer-clean phenomena: tiny bubbles on the wall of the glass. While it appears innocuous enough, don’t be fooled! Those tiny bubbles are actually some form of film, bacteria, or incompletely rinsed liquid that are serving as nucleation points for carbonation. In other words, carbon dioxide is sticking to those little bits of gross and bubbling up from there, instead of staying in the head of the beer or in solution. The result is a head that collapses within minutes, the entire beer goes flat, and/or potentially tastes more like dirty socks than beer. To me, this is the ‘dirtiest’ of the major issues because the off flavor it produces can be so overpowering.
Leftover chemicals are another impediment to achieving beer-vana. Usually caused by detergent or sanitizer that was too powerful (and thus didn’t rinse completely), this one tends to cause a Band-Aid-ish aroma. It sort of smells like your drinking establishment is in a hospital. The good news is that the chemicals won’t hurt you, even if it renders your beer un-enjoyable. Some readers will be wondering why sanitizer is the last step instead of rinsing if this chemical can so ruin beer. The answer is that in the proper proportions, Star San (or similar) is neutralized by contact with water or beer. When concentrations get too high, that is when drinkers run into unpleasant aromas or flavors.
When you see a bartender rinse the inside of the glass with water quickly before pouring beer into it, she or he is trying to rinse away any residual chemicals or whatever else. It also gives your bartender an extra second to visually inspect the glass for unwelcome signs of the previous glass user. Not every beer bar takes this extra step, and ultimately it is not necessary, but it is a nice extra touch to show that the establishment cares about your beer.
Cleaning glasses for beer at home is usually as simple as running your glassware though the dishwasher, which has enough pressure and temperature to cure most of these common issues. Those of you that homebrew could assure beer clean by using a spot of whatever brewing sanitizer you use in a full sink of hot water to rinse dishwasher-clean glasses.
And always remember that it is perfectly alright to send a glass of beer back because you pick up something off. If you are unsure the aroma/flavor/etc is not right, politely ask your server if they know what it is supposed to be like. If you spot clear signs of an unclean glass, any place worth their hops will fix it for you immediately and without question.