Guinness "Brewhouse" promotion circa 2006

enda1

BaZmO* wrote: »

I was always under the impression that Extra Cold was just done the way that guildofevil described. Think I was working in a bar at the time too and the only difference was the extra end of line chiller. Although I'm not 100% sure on that.

Does make some sense that it could be just that cause the extra burst of nitrogen decompressing in the injection and beer should cool the beer because a gas decompressing (and instantaneously boiling) lowers in temperature.

Blisterman

In the pub I worked in, they ran the extra cold Guinness through the chiller twice, rather than once for Regular Guinness.

BeerNut

So would the different top just have been a way for Diageo to track sales?

BaZmO*

BeerNut wrote: »

So would the different top just have been a way for Diageo to track sales?

Yeah I suppose it make sense alright as there would be no way of knowing how many were sold otherwise.

guildofevil

enda1 wrote: »

Does make some sense that it could be just that cause the extra burst of nitrogen decompressing in the injection and beer should cool the beer because a gas decompressing (and instantaneously boiling) lowers in temperature.

You are confusing a change in state with a gas coming out of solution. The nitrogen dissolved in beer is not liquid nitrogen, it is a gas dissolved in a liquid, but it is still a gas. All that is happening it a gas going from an area of high concentration to an area of low concentration, which will not result in any thermal gain or loss beyond that you would expect for a cold liquid in a warm atmosphere.

Another thing to consider is that there is not actually a very big difference in the concentration of nitrogen in the beer and nitrogen in the air. The Atmosphere is 78% nitrogen, so the nitrogen in the beer tends to just sit there, which is why nitrogenated beers give off less flavour and aroma and why you get a creamy head that lasts to the end of the glass. Carbon dioxide, by contrast is in quite low concentrations in the atmosphere, so it rushes out of solution bringing the flavour and aroma with it.

If gas coming out of solution (as opposed to changing state) caused the liquid to cool down, co2 would be a far more effective chiller than nitrogen as it is far less stable in solution.

enda1

guildofevil wrote: »

You are confusing a change in state with a gas coming out of solution. The nitrogen dissolved in beer is not liquid nitrogen, it is a gas dissolved in a liquid, but it is still a gas. All that is happening it a gas going from an area of high concentration to an area of low concentration, which will not result in any thermal gain or loss beyond that you would expect for a cold liquid in a warm atmosphere.

Another thing to consider is that there is not actually a very big difference in the concentration of nitrogen in the beer and nitrogen in the air. The Atmosphere is 78% nitrogen, so the nitrogen in the beer tends to just sit there, which is why nitrogenated beers give off less flavour and aroma and why you get a creamy head that lasts to the end of the glass. Carbon dioxide, by contrast is in quite low concentrations in the atmosphere, so it rushes out of solution bringing the flavour and aroma with it.

If gas coming out of solution (as opposed to changing state) caused the liquid to cool down, co2 would be a far more effective chiller than nitrogen as it is far less stable in solution.

The nitrogen in the cylinder is a liquid I thought, no?
So its expansion into atmospheric pressure will cause a huge temperature drop as thermal energy must be used to boil the liquid to gas.

Gang of Gin

Lilah Green Form wrote: »

Hello gang. I seem to remember a promotion Guinness had going on a few years ago where they would brew Guinness using the same methods and ingredients of certain times past called "Brewhouse".

The reason I ask is because I remember hearing that it was supposed to go on for ages, yet they quit after only two or three new-old varieties of Guinness were released.

At the time, I didn't drink Guinness so I despair now at what I missed out on. Can anyone here shed any light on why they stopped this and maybe how the Brewhouse Guinness' tasted in comparison to the original?

The Brewhouse Guinness was somewhat of a lite version of Guinness. A tame, almost Beamish-like. I'm not sure which one of the few they released it was but it was only okay, albeit certainly drinkable.

BeerNut

enda1 wrote: »

The nitrogen in the cylinder is a liquid I thought, no?

It's a nitrogen/CO2 mix, and it's a gas in the cylinder. I'm guessing liquid nitrogen is a bit dangerous for Paddy the Drayman to be heaving tanks around.

guildofevil

enda1 wrote: »

The nitrogen in the cylinder is a liquid I thought, no?
So its expansion into atmospheric pressure will cause a huge temperature drop as thermal energy must be used to boil the liquid to gas.

Actually, no. The nitrogen in the cylinder is a gas under pressure (actually a mixed gas of 75% Nitrogen, 25% co2), not liquid nitrogen. Liquid nitrogen requires temperatures and/or pressures which make it dangerous to handle. Not something you want or need in your average pub cellar.

An example of a gas which is shipped in liquid form is LPG. You will be familiar with the yellow Calor Kosangas cylinders. This gas is shipped in liquid form because it doesn't take a lot of pressure to keep it liquid. The reason I mention this is that it illustrates what happens when a liquid changes to a gas.

As the cylinders empties, the pressure drops and the liquid changes to a gas. This happens in the cylinder, so you have a layer of gas sitting on top of the liquid at the bottom of the cylinder. This meas that this is where the thermal change happens. It is the cylinder that gets colder.

Another thing to consider is that the beer comes with the nitrogen already dissolved into it. The mixed gas cylinder in the pub cellar is just there to keep the pressure up in the keg as it empties.

vektarman

guildofevil wrote: »

co2 would be a far more effective chiller than nitrogen as it is far less stable in solution.

This is correct, Guinness Extra Cold had a higher CO2 content than regular Guinness and it's added before keg filling.

mikep

Jeez...all this extra cold talk is making me feel guilty so I'll come clean!
Prior to the introduction of the extra cold I took part in a tasting panel for Guinness...
Once a week for five weeks I and about 20 other guys were given 5 pints to drink and had to complete a questionnaire...As I recall this was during a lovely summer (remember them??) probably 1995, so perhaps we favoured the extra cold as the weather was hot...I vivdly remember the quality of the pints and also the fact that they checked the temps before giving them to us...Best part was we also got paid for it!!! happy days!:D:D

BTW I believe that all guinness is now served extra cold except for in some pubs which kept the old temps...

I personally think it is served far too cold nowadays.