What is the head on beer/stout made up of?

az2wp0sye65487

After finishing a pint of Guinness last night I noticed that as usuall there is still some of the creamy 'head' in the end of the glass...

I got to thinking, when it's first poured and is setting a lot more of the pint seems to consist of the 'head' until it settles and turns black and liquidy. But by the time you get to the end of it there is some 'head' remaining... What makes it different to the rest of the pint?!?!?

saefraigh

As the beer pours through the tap, it passes through a plate with holes in it designed to mix the "insoluble" nitrogen and the beer. This creates the foamy head the same way a steamer on an espresso machine makes foam with milk. Because the nitrogen binds with the beer, it will remain after the pint is gone, but not for too much longer. The "creamy head" is just a marketing invention.

Nitrogen actually disguises the flavour of stout, try Trouble Darks Arts porter at the B&C christchurch(they only serve it on Co2) to see the difference in flavour. Or Dungarvan's Black Rock Stout.

chin_grin

saefraigh wrote: »

As the beer pours through the tap, it passes through a plate with holes in it designed to mix the "insoluble" nitrogen and the beer. This creates the foamy head the same way a steamer on an espresso machine makes foam with milk. Because the nitrogen binds with the beer, it will remain after the pint is gone, but not for too much longer. The "creamy head" is just a marketing invention.

Nitrogen actually disguises the flavour of stout, try Trouble Darks Arts porter at the B&C christchurch(they only serve it on Co2) to see the difference in flavour. Or Dungarvan's Black Rock Stout.

I was about to say "dead hopes and dreams". But that's WAY more informative.

BeerNut

Further to what saefraigh says, nitrogen is used for this because air is mostly nitrogen. There's less much incentive for the gas to dissipate into the air the way carbon dioxide does, so nitrogen bubbles hang around longer. That's why they're still there at the end of your pint. That's also why it disguises the flavour of beer: the bubbles aren't driving the flavours out of the beer and into your taste centres the way carbon dioxide fizz does.

Blisterman

In answer to your question, in adddition to CO2/Nitrogen, protein from the malt causes the head in beers. Hence why coke never retains a head, while beer does.

az2wp0sye65487

Cheers lads....

Amusing as well as informative!

:pac: