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Nov 7, 2013 06:48 PM

Cleaning wine glasses with isopropyl alcohol?

Someone just told me they use a spray bottle of rubbing alcohol to polish wine glasses at their restaurant. Is it safe, or is it a bad idea? This was the first I've heard of it. I tried it and it works better than steam, but I'm not really sure about residue or side effects.

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  1. First, be careful with the term "rubbing alcohol." That can refer to either isopropyl alcohol or denatured ethanol. Denaturants are substances added to non-beverage ethanol to make it non-potable. Unfortunately, a common one, denatonium benzoate, leaves a residue, and is the most bitter chemical known to man.

    Isopropyl rubbing alcohol, on the other hand, in theory is just isopropyl alcohol and water, both of which should evaporate leaving nothing. In practice, there might be minor impurities which are harmless for the intended purpose as a disinfectant, but might leave an undesirable residue.

    1. There's very little toxicity from such a small amount of isopropyl alcohol but it's still a very bad idea.

      The worst effect is the way rubbing alcohol will change the perception of flavors in the wine. Isopropyl's residual smell will certainly throw off the wine's aromatics, leading the taster to think the wine is high in alcohol when it isn't.

      Isopropyl is used to clean glass, but not glass that will have liquid in it or food on it.
      Please tell your friend to not use it, even if the isopropyl is diluted.

      1. Isopropyl alcohol has low toxicity and the body can process small amounts of it, but I wouldn't do this.

        1. Bad news for all of the above reasons, and I'm guessing the local health/sanitation folks wouldn't smile on the practice.

          You might suggest they use a little cheap vodka in the spray bottle, as it will at least not leave toxic/offputting residues/aromas.

          1. I'm curious as to how prevalent the use of steam is to polish glasses. I'm certainly not a veteran of high-end venues but I've been around a bit and I've never even heard of it.

            I DO know that drying with a special polyester cloth seems to work best when the glasses are still pretty warm from a glass machine or a hot rinse.

            Is steam better than hot water.... and why? It seems like a lot of extra work.

            7 Replies
            1. re: Midlife

              Hi Midlife,

              All the glasses in question have been washed in a dishwasher. The reason we use steam is just to help remove any stubborn water spots. We could dunk the glasses back in water but it's a lot more work to dry a entire wet glass than a little spot where there's a little moisture from some steam. Some fine dining places where I have worked polish everything from water glasses to wine glasses, which means there are literally hundreds of glasses that need to be polished at the end of the night. Sometimes over 500 glasses. It takes hours.

              I was already aware isopropanol has some toxicity. Isopropanol is approved for use in food surface sanitizers, and there are a quite a few "no rinse" food surface sanitizers that are 70% isopropanol, but it's not something that I want around all me the time, which is why I asked the question. I tried 190 proof Everclear, but it has something in it that leaves a couldy residue, so I guess I'm going back to steam.

              As far as residual odor, there is none once the alcohol evaporates. In fact, the reason the conversation came up was because I was always impressed how clean this sommelier's glasses looked and smelled. When I tried it myself I was kind of shocked how clean the glasses smelled. Even with an immaculate microfiber towel I can usually smell a little bit of a lint or dusty smell for up to 60 seconds, but the glasses cleaned with alcohol had zero odor once they dried.

              1. re: la2tokyo

                If your friend's restaurant is having to do that much polishing, or resorting to isopropyl (or isopropanol), something is very wrong, IMO, with the way they are washing glassware.

                They're wasting time and labor (both mean money) that they shouldn't be spending.

                I'd look first to the no-rinse cycle. Do you know how these work? Instead of a very hot water rinse, dishes or glassware are dunked into a solution. But the solution leaves a film. Which your friend then has to spend hours polishing off.

                The dunking solution uses QATs -- quaternary ammonium compounds -- or other equally potent chemicals to "sanitize" dishes. Trouble is, no-rinse cycles neither get glasses clean or sanitize. The residue of disease-causing pathogens left on dishware/glassware/silverware treated with a final a no-rinse cycle was far higher than that left by plain ole extremely hot water.

                I know because I was asked to analyze several studies on QATs and no-rinse cycles
                and pathogens. I never would be writing here had I not done that, and also worked for wineries that had stunning glassware with far less work. No-rinse cycles are not the way to go for several reasons.

                I can't solve your friend's problem. But I can offer suggestions:

                Wash glassware in a machine designed to wash only glassware. Do not wash glasses in the same machine as dishware and silverware. Some of the film deposited on glasses is actually dissolved organic matter (food residue), just so you know.

                Go back to plain old extremely hot water for your final rinse instead of a no-rinse cycle, which leaves a film.

                Use as little detergent as possible that still gets glasses clean. Detergent leaves a film.

                Don't add more detergent to the cycle because lipstick marks are still on the rims of glasses -- those glasses always require special handling: wiping rims by hand after the first wash cycle and then re-washing. That would be the only time I would ever approve of using isopropyl -- to wipe stubborn lipstick residue -- and only if the isopropyl was going to be washed off afterwards.

                Don't use a rinse aid: They also leave a film. They work by breaking the surface tension of water so that it doesn't form droplets or beads, which then dry on the surface of the glasses, and then has to be polished off.

                Pay special care to how you treat the glasses once they come out of the dishwasher. Do they sit and air dry??
                Bad move. Lots of water spots on glasses that way.

                Research the content of your water. Hard water, soft water? Minerally? Lots of lime? That will leave a tough residue. The content of your water will also change the way you wash glassware.

                You can try adding citric acid to the wash cycle, but it doesn't always work. Do research on what what restaurants and wineries with sparkling glassware do in your area.

                If your friend has to use vodka or isopropyl to clean glasses because a *quick* wipe with a Riedel glass cloth (or something comparable) does not do the trick, the problem that's causing the dirty glassware has not been identified.

                That's the goal for this issue: identify all the things that are causing a film or water spots. Since your friend has not identified the problem, his/her solution is not a good one either.

                BTW, for all the labor costs going into polishing glassware, a new glassware washing machine could pay for itself.

                1. re: maria lorraine

                  Thanks for the reply. In all the places I have worked, which is six restaurants, everything got polished every day. Maybe I had really bad luck, but I don't know anyone who works in fine dining at other Michelin-Star type of restaurants who doesn't polish wine glasses. I'm not talking about a lot of heavy polishing, but the glasses are still polished. Most of the glasses were already very clean, but we still have to look for spots. Many of the problems you cite sometimes exist to some degree. Bad water, too much detergent etc, etc., although every restaurant I worked in did have water softeners. If we had the privilege of multiple dishwashers, I imagine machines specifically designed for glassware like Miele would be great, although as far as I know they don't make a commercial washer. Health inspectors require the use of sanitizer, and even with water softeners, with one machine for everything there are sometimes spots. Most of the time it is just a quick wipe with a Riedel cloth, like you said, but at the end of the day that's still 500 glasses that require a quick wipe. Sometimes more, and that's not even counting the Riedel Somm glasses that get washed by hand. With a hundred guests, and people doing wine pairings with a dozen or more glasses, there are a LOT of dirty glasses. When you're working in a place that is serving $5,000+ bottles of DRC, one tiny spot on any of those 500 glasses is not an option. I'm not saying there's any need to use alcohol out of necessity, ever. However, it would be nice to have a spot remover that works better than water, because when you have that many glasses, something that saves two or three seconds per glass is a lot.

                  1. re: la2tokyo

                    Look, I don't care if you take my suggestions or not, but something is obviously wrong with all the human labor being put into this, when most of the labor would go away with a great glassware machine.

                    Seems like a place that serves $5000 DRC could afford a machine dedicated to glassware that does a brilliant job.

                    <<In all the places I have worked, which is six restaurants, everything got polished every day. Maybe I had really bad luck, but I don't know anyone who works in fine dining at other Michelin-Star type of restaurants who doesn't polish wine glasses. I'm not talking about a lot of heavy polishing, but the glasses are still polished. Most of the glasses were already very clean, but we still have to look for spots. >>

                    When did I say you wouldn't have to polish even with a great machine? You will always have quick glass polishing in fine dining, but the burden of doing so must split up among workers.

                    Miele makes commercial glassware washers, AFAIK. But there are other brands also.

                    <<with one machine for everything there are sometimes spots.>>

                    More than spots, as I've explained.

                    The assessment of the problem is as much of a problem as the other problem.

                    I've offered several solutions. Feel free to use them or not. I regret taking the time to help.

                    1. re: maria lorraine

                      The reason I'M interested on this is that the chef at the place I work requires that all wine glasses be 'polished' with a Riedel-type cloth again AFTER they been washed, rinsed, sanitized in a 3-compartment sink AND dried completely with a Riedel cloth. If the glass us spotless, when held up to light after the first 'Riedel-ing', I've never understood the second 'polish'. I guessed that her concern was spots left after the first 'Riedel-ing' but, without the above-described steam, I'm skeptical that more polishing would do much good on glasses left to sit a while.

                      The water is very hard around here, so spots do require serious attention. It just seemed more logical to me to dry and polish as one operation if the last rinse is in hot water. You just have to use a number of alternating coths so you really do dry well. Is that wrong?

                      1. re: Midlife

                        Hi Midlife,

                        We don't polish twice. A group of about six people dries the glasses after they come out of the dishwasher with Riedel or similar microfiber towels while they are still wet and hot. Most of the glasses are spotless after this. Sometimes there are spots from guests with sticky stuff on their fingers or thick lipstick, so a little moisture helps to remove it. Some people use a slightly damp part of their towel, I prefer to have a electric tea kettle running in front of me so I can apply a tiny bit of moisture with the steam and rub the spot off that way. The whole process is fast and efficient, but when you have multiple stacks of glass racks that go from floor to ceiling it takes a while. I did work at one place where they polished again after towel drying, as you describe, and I didn't really understand that either. I think it was just to make sure that there were no fingerprints and that the crystal really shined brilliantly, but I don't think the effort was justified.

                        1. re: la2tokyo

                          Get it! These glasses were far from crystal anyway.