Dirty Guinness Glass?

alspants

Hello,

If any body can settle a dispute I am having I would be grateful.

You know when you get a guinness and there is swashes of bubbles along the side of the glass so that it looks dirty. It literally looks like lines of dirt.

I am convinced that it is grease that is causing the bubbles to cling to sections of the glass.

When I complained recently, and complaining to a barman about a dirty glass is equivalent to slandering his mother or something, he insisted it was condensation angrily.

Why would there be condensation on some glasses and not others?

Is it not enough rinse aid in the glass washer?

If you use a dishcloth and vinegar to clean grease away you do not get this selective "condensation"

Just wondering, dirt or condensation?

Alspants.

BeerNut

It wouldn't be grease, since that prevents the nucleation points which cause bubbles. Condensation would be on the outside so if it were that it'd wipe off, obviously. It could be dirt or fluff or whatever, or it could just be flaws in the glass. It'll have been sterilised so is fine.

The world was a better, simpler place when all beer was served from clay pots...

irish_goat

Those bubbles are caused by tiny marks on the inside of the pint glass caused by glasses scraping against one another when they are stacked together. Doesn't make a difference to the taste of the pint.

IrishWhiskeyCha

I've seen this a few times and sometimes yes the pint is muck.

The scratch theory sounds plausable but does not account for a muck pint. My theory for a muck Guinness with this phenomena is possiblely minute dried in detergent residue.

irish_goat

A muck pint could be any number of reasons, badly cleaned pipes, bad keg, no or wrong gas, dodgy cooler etc. Dried detergent residue is unlikely though as any decent barman would notice straight away if their glasswasher isn't rinsing glasses properly. For one thing, the glasses would almost slip out of your hand if there was detergent on them.

IrishWhiskeyCha

irish_goat wrote: »

Dried detergent residue is unlikely though as any decent barman would notice straight away if their glasswasher isn't rinsing glasses properly. For one thing, the glasses would almost slip out of your hand if there was detergent on them.

IrishWhiskeyCha wrote: »

... minute dried in detergent residue.

Why would it slip out of your hand when the glass is dry I'm not talking about it being covered in sudds ... remember we are talking about the inside of the glass too. I reckon that if there is too much detergent or rince aid in a washer it leaves a residue or coating on a glass. This is virtually impossible to see as the glass looks clean.

shanel23

A few years ago I did some "quality testing" for Guinness - through a marketing agency . The testing involved going to specific nominated pubs and buying a pint and evaluating the pint. As part of the testing we did some training at the hopstore with a guinness rep. - The four critera that were being measured were

1. Was the pint served in a guinness branded glass ?

2. Was there overspill when you recieved the pint ?

3. Was the head the right size - they provided a credit card sized measure which was to be used to measure the head from the top of the glass.

4. Finally was the glass clean - the test for this was no streaks or lines of gray bubbes on the inside of the glass.

The biggest failure was 4 - this was caused in 90% of cases where the guinness glasses were washed in the same dishwasher as cutlery and delph. Grease from the delph and cutlery contaminated the glass . Guinness themselves stipulate that guinness glasses should be washed separetly to delph ( I think Guinness provide glasswahers to pubs ) .

So I would say that your gray lines are not condensation but a dirty glass contaminated by grease - the barman for sure is right when he says the glass was washed - it's just that they were not washed separetly from delph.

-Corkie-

If the pub/bar in question serves food it also leaves the pint like muck. A fella from guinness told me that when people have pints of milk with their dinner it leaves the next pint like muck. I cant understand this if the glass is washed properly. Maybe its grease from peoples mouth as said in the first post. My experience is drinking in restraunts is always getting guinness that isnt that great. Hope some of ye can elaborate on this....

Wine_Guy

shanel23 wrote: »

The biggest failure was 4 - this was caused in 90% of cases where the guinness glasses were washed in the same dishwasher as cutlery and delph. Grease from the delph and cutlery contaminated the glass . Guinness themselves stipulate that guinness glasses should be washed separetly to delph ( I think Guinness provide glasswahers to pubs ) .

Can be true, but glasses left to cool in the glass washers have not drip dried properlyand can hold cool water on the inside of the glass, bubbles stick to this water, as for the scrapes, yes they do happen from glasses but are not the cause of sticking bubbles.
Unfortunatly some places do use a glasswasher as a dishwasher aswell and has every chance of holdeing grease. Grease can be very hard to get out of these machines, virtually impossible.
Another factor for the greasy glass is the use of washing up liquid in pubs. these products contain animal fats, which is why they leave your plates shiny, but destroy glasses, especially if they are combimed with the heat of the glasswasher.