I have a friend who refuses to drink beer from any glass that ever had milk in it. He believes milk does something to the glass that persists through washings, and he claims it somehow ruins his beer drinking experience.
I drink beer directly from the bottle, and all of my pint glasses have been used for milk.
Anybody ever heard of this? I find it hard to believe that after washing the glass in the high temperature soapy water of an automatic dishwasher that anything remains bonded to the glass.
Yep, sounds pretty silly. But you wanna know something? A beer connoisseur would say that say that you are contaminating the glass. According to Those Who Know[sup]TM[/sup], a beer glass should never be washed with soap and water, as there is a belief that it’s next to impossible to get all the soap out of the glass. Instead, they say you should wash the glass with water only.
Both of those ideas are pure silliness. Glass is inert and nonporous, and doesn’t adsorb substances well at all. Zero remains of the milk after washing, and no soap is left behind after a thorough rinsing.
Not silly at all, certainly if milk dries in the glass. Milk protiens have been used for centuries to make an extremely tenacious paint. Most modern paint strippers won’t touch the stuff so it’s no suprise that diswashing detergent may not get every bit of residue off the surface. Glass may not be porous but there are plenty of things that will adhere like a mo-fo.
Rinse agents used in dishwashing may prevent or reduce head production or retention that beer connoisseurs use to judge the quality of certain beer styles.
Q.E.D. is correct in theory - glass is pretty amazingly inert stuff, and after a thorough rinsing (and allowing it to dry), you’ve got, well, glass. However, beer is amazingly fussy stuff, and the average householder won’t wash, rinse, and dry the glasses adequately. Household dishwashing liquid doesn’t really agree with beer, and most people’s glasses still have traces after they have been cleaned. This is why a beer in a pub maintains a nice foamy head, but a beer poured into an old honey jar by your Uncle Robbo will lose its head in seconds.
To have “pub beer” at home: do keep dedicated beer glasses (most good pubs do). No milk, no soda, no five year-old’s grubby fingers, no nuffin’ except beer. Go to the homebrewing section of your supermarket or to a specialist store and pick up some bottle washing powder. Wash your glasses thoroughly with this stuff (making sure you wear gloves), and rinse them two or three times. Allow them to air-dry on a rack (don’t even think about using a cloth), and when they are dry and beer o’clock is approaching, chill them. Always keep your fingers away from the rim.
If all this is too much trouble (it usually is for me), just drink it from the bottle.
Why don’t you test your friend? You’ll need a third friend to keep it double-blind, but easy enough to do.
Buy a couple of pint glasses (or better yet, a few pairs). Put milk in one, then wash them both. Now get the third friend to put a blue sticker on one and a red sticker on the other, writing down which one was the pre-milked glass, but not telling you.
Now serve your friend beer in the two glasses and ask him which glass was pre-milked (your third friend shouldn’t be in the room at this point, so that the tester can’t pick up any cues from their reactions). Check to see if he guessed right. If he can guess right significantly more than half the time, he’s on to something. If not, well…
But what’s “thorough?” I can wash a glass w/ soap, fill it with water, dump, fill it with water, dump, etc. Even after 4 or 5 cycles I can still see a tiny vestige of soap bubbles. As with most things, the quantity of soap molecules vs. rinse cycles is likely a logarithmic function; the more times you rinse, the more soap you get out of the glass, yet it’s next to impossible to get 100% of the soap out. If you rinse 4 or 5 times, would a beer connoisseur be able to detect the few remaining soap molecules? I don’t know, and I suspect no one has ever done a double blind/controlled test.
As far as automatic dishwashing soaps go, I believe many soap manufacturers add a chemical to inhibit water spots during drying. Does this leave a film on the glass?
There are too many unanswerable questions here. The bottom line is that, in all probability, a typical rinsing never removes every last soap molecule. Whether or not a beer connoisseur can detect an ultra-low contamination level is a matter of debate.
Detecting the soap isn’t the question. The problem is that soap, milk, etc. destroy the beer’s head. There is virtually no way to completely clean a glass that has had these substances in them at home. TheLoadedDog has it right…dedicated beer glasses.
[quote[ As far as automatic dishwashing soaps go, I believe many soap manufacturers add a chemical to inhibit water spots during drying. Does this leave a film on the glass?[/quote]
It’s called a “drying agent”. What it does is somehow or other make the water “wetter” than it normally is. Because of the increased “wetness”, the film of water on the surface will be thinner, and will evaporate much more quickly than otherwise. Water spots usually appear where the water has beaded up on a surface. The drying agent inhibits the formation of beads, forcing the water to run off in a solid sheet. When the water evaporates faster, the mineral particles don’t have time to drift toward and stick to the dish surface.
I will hazard a guess that the drying agent does this by reducing the adhesiveness of the water molecules, which would effectively lower the surface tension, preventing beads from forming.
Drying agents (sometimes called “rinse agents”) are used in dishwashing machines in most restaurants and bars. One reason is, naturally, to avoid spotting; the other reason is quick drying. Health codes prohibit towel-drying of dishes (bacteria accumulate quickly on damp rags), so all dishes must be air-dried. And in a busy bar or restaurant, you want those dishes to air-dry as quickly as possible so that you can stack them and get them out of the way of the next batch of dishes.