http://www.independent.co.uk/news/sc...nt-868543.html


How to get a head: In search of the perfect pint

We've been drinking beer for centuries. But only now are scientists learning
the secrets of the perfect pint. Sanjida O'Connell learns the recipe for
success from the master brewers

Wednesday, 16 July 2008

"It's a drink that is almost as old as civilisation: beer was originally
made from emmer, an early form of wheat, by the Babylonians who offered it
to their gods. In this country, it was made mainly by women, known as beer
witches; the last witch was burnt alive in 1591 for her bad brew. But until
Louis Pasteur discovered that micro-organisms cause fermentation in 1860, no
one understood what turned a gloopy slop of grain into a potent pint:
brewers used to add beer from the previous batch and call it 'godisgoode'.

"It's a magical process," says Adrian Tierney-Jones, writer and beer expert.
"Brewers never fail to be fascinated at how a beer turns from being lifeless
to full of life." Alex Bell, head brewer for O'Hanlons, will explain to the
Royal Institute tonight how scientists have finally got a handle on the
magical alchemy of beer brewing. As Bell says, "The key thing in the brewing
process is making alcohol." We now know it's the yeast that's responsible:
it's a type of single-celled fungus, which produces the fizz and
intoxication - alcohol and carbon dioxide. It takes 34 million of these
cells to produce just one pint of beer.

The starting point for most beer is barley. The grains are soaked and then
left to dry until they begin to germinate. To prevent them turning into
mini-barley plants, the grains are heated and crushed. This malted barley
smells of lightly toasted granary bread but the grain turns darker and
richer at higher temperatures: crystal is a mixture that has toffee and
biscuit flavours and roasted barley, used to make stout, looks and smells
like ground coffee.

"What malted barley adds to beers are roasted and smoky aromas and coffee,
chocolate, bready, biscuity, sweetcorn, hay, toffee, caramel and
butterscotch flavours,"says Tierney-Jones.

The malted barley is heated with water to release enzymes that break the
complex starches into simple sugars like glucose and maltose. Other enzymes
chop the proteins in the grain into shorter segments. This wort, as it's
called, is drained out and the remaining mashed barley is fed to the local
cows. The wort is pumped into a brewing kettle where it's boiled with hops.

It was Belgian monks who first added hops to beer approximately 500 years
ago. Before that a range of ingredients were used to impart flavour such as
juniper berries and bog myrtle and even henbane, which is a hallucinogen.
"The monks were allowed up to five litres of beer a day when they were
fasting," says Bell, "so they took beer seriously."

The proper name for hops is Humulus lupulus; lupulus is derived from the
Latin for wolf. A wild climbing vine, they're now grown by training them up
10ft vines. It's the flower, the "cone", that contains most of the unusual
and complex chemicals that impart bitterness, aroma, antioxidants, enhance
foam production and act as an anti-bacterial. Normally two types of hops are
used - ones that add bitterness from humulone, an astringent acid - are
boiled with the wort for at least an hour, whereas aroma hops are added
towards the end of boiling so that they release their aromatic oils without
the oils being evaporated. O'Hanlons uses dried hops from America, the UK
and the former Czechoslovakia, which smell of Thai spice - of lemongrass,
galangal and coriander. Tierney-Jones says, "Hops add herbal, grassy and
lavender aromas as well as bitterness, spiciness and citrus, and tropical
fruit flavours." The mixture is then left to ferment with yeast for up to
five days. "After 24 hours, the yeast foam looks like a lemon meringue pie,
the peaks are astonishing," says Bell. "What yeast adds to beers are the
flavours and aromas of soft fruit," says Tierney-Jones. There are two main
species of yeast: Saccharomyces cerevisiae, which works at warmer
temperatures and is used to make bitter and ale, and Saccharomyces
carlsbergensis, which needs cooler temperatures and creates lager. There are
more than 500 strains of these two main species, often particular to a
brewery. The larger brewers send their yeast to be stored in labs so that if
anything goes wrong, they can recultivate their own strain.

Yeast converts the sugars from the barley into carbon dioxide, which gives
beer its fizz, and alcohol. It's called the glycolytic pathway and its
extremely metabolically inefficient as the yeast hardly recoups any energy
from the process. "Yeast would gain more energy if it converted the sugars
into carbon dioxide and water, as we do, but we're grateful that it
doesn't," says Bell.

The by-products of this process are the production of other compounds that
contribute to the flavour of the beer. For instance, the final step in the
pathway is the conversion of glucose to the compound pyruvate. This is then
converted into ethanal, which can then be turned into ethanol (alcohol);
sometimes though, the ethanal gets converted to diacetyl. This chemical
produces butterscotch flavours that are good in stout but not so welcome in
other beers. Leaving the mixture for longer allows the yeast to turn the
diacetyl into 2, 3-butanediol, which doesn't taste as strongly of
butterscotch. Saccharomyces cerevisiae strains of yeast produce esters, such
as isoamyl acetate, which tastes of pear drops and bananas, and ethyl
hexenoate that has an appley aroma.

The beer is then put into casks or bottled and a secondary fermentation will
take place that produces the carbonation. "There are so many factors that
can change the finished product," says Bell, who has created a beer called
Fire Fly, "the weather, the barley, which affects the range of proteins, the
amount of oxygen in the beer that's added during mixing, the dynamic of the
boil. The beer in your glass might not taste anything like you'd planned."

What determines whether a beer is an ale, a bitter or a larger is down to
the amount and type of hops as well as the malted barley, but is primarily
due to the strain of yeast. "A yeast that has been used for the same beer
over a period of time will have a specific character and adds its own
particular imprint to the beer. Different yeasts produce different flavours.
O'Hanlons produce a beer that contains 12 per cent alcohol, lasts up to 25
years and is almost scarlet in colour when you hold it up to the light. It's
named after Thomas Hardy, who wrote in The Trumpet-Major: "It was the most
beautiful colour that the eye of an artist in beer could desire; full in
body, yet brisk as a volcano; piquant, yet without a twang; luminous as an
autumn sunset." Not quite what those Belgium monks might have expected from
the action of a fungus and a wild wolf plant..."

</>

Gregory wrote on Wed, 16 Jul 2008 16:30:19 -0500:

> How to get a head: In search of the perfect pint
>>>Much clipping<<<<<

Very interesting but "Perfect Pint" is possibly an English or Irish but
hardly an American expression especially as there are often no
indications as to how much you are getting of a draft beer. I wonder if
Scots worry about it too since the measure there is the top of the glass
and the foam is supposed to spill over. Are the marked glasses actually
Imperial pints in Britain and Ireland?

--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not

"Gregory Morrow" > wrote in message
...
>
>
> http://www.independent.co.uk/news/sc...nt-868543.html
>
>
> How to get a head: In search of the perfect pint
>

Now you do know that every person who saw this header was going to read
this, right?

Kswck wrote:

> "Gregory Morrow" > wrote in message
> ...
> >
> >
> >
http://www.independent.co.uk/news/sc...nt-868543.html
> >
> >
> > How to get a head: In search of the perfect pint
> >
>
> Now you do know that every person who saw this header was going to read
> this, right?


Like flies to, uh, honey...

;-)

[I'll let the gals around here have the header "How To *Give* The Best
Head"...I'll not mention any names, this being polite mixed company 'n
all...]


--
Best
Greg

"Gregory Morrow" > wrote in message
m...
>
> Kswck wrote:
>
>> "Gregory Morrow" > wrote in message
>> ...
>> >
>> >
>> >
> http://www.independent.co.uk/news/sc...nt-868543.html
>> >
>> >
>> > How to get a head: In search of the perfect pint
>> >
>>
>> Now you do know that every person who saw this header was going to read
>> this, right?
>
>
> Like flies to, uh, honey...
>
> ;-)
>
> [I'll let the gals around here have the header "How To *Give* The Best
> Head"...I'll not mention any names, this being polite mixed company 'n
> all...]
>
>
> --
> Best
> Greg

ROTF.


--
Old Scoundrel

(AKA Dimitri)