The accidental science of beer

Beer is alive I tell you! Alive!
Beer is alive I tell you! Alive!

Our post on Fri­day prompt­ed some needling from Alan at A Good Beer Blog: brew­ing great beer isn’t hard – it’s a ‘sim­ple, tra­di­tion­al skill’. Then today, as promised, Ed chipped in with a typ­i­cal­ly sharp post query­ing how we end­ed up in what seems a top­sy-turvy world where stain­less steel automa­tion is ‘craft’ and beer brewed using tra­di­tion­al meth­ods isn’t. (It is to us, but our attempts to reclaim the word to include cask ale seem to have failed.)

With all that in our minds, it was odd that, from beyond the grave, Michael Jack­son should chip in from the pages of an issue of The Times from 1980, remind­ing us that brewing’s sta­tus – art, craft, sci­ence, or some­thing else? – has been con­fused for a long time, and is far from set­tled:

For all the painstak­ing research that has been done on the sub­ject, brew­ing remains less of an exact sci­ence that it is an art. “Only recent­ly have we begun to under­stand what a remark­able art it real­ly is”, Pro­fes­sor Antho­ny Rose, a micro­bi­ol­o­gist wrote in the Sci­en­tif­ic Amer­i­can some years ago. “The brew­mas­ter, by tri­al and error, has been manip­u­lat­ing some of the sub­tlest process­es of life.”

(Rose’s arti­cle, ‘Beer’, appeared in the June 1959 edi­tion of the mag­a­zine, and lives behind a pay­wall here.)

Do brew­ers with degrees, labs and ref­er­ence libraries, who under­stand why they do what they’re doing, make bet­ter beer than those who just knew it worked?

Jurassic Park

Raul Cano has suc­cess­ful­ly cul­ti­vat­ed yeast from the con­tents of the bel­ly of an insect trapped in amber 45 mil­lion years ago. That’s mind­blow­ing enough.

When you hear that he’s entered into busi­ness with a brew­er to pro­duce Fos­sil Fuel Ale using this ancient, super-stur­dy yeast, it just gets cool­er.

Appar­ent­ly, it acts like ale yeast at first, fer­ment­ing furi­ous­ly at the top, before sink­ing to the bot­tom to car­ry on work­ing.

Read the whole sto­ry at Wired.

And Alan spot­ted this last year, of course, well before Wired got onto the sto­ry…

Nice branding can make things taste better

Nicely branded Sierra Nevada Anniversary Ale
Nice­ly brand­ed Sier­ra Neva­da Anniver­sary Ale

We’ve always felt slight­ly guilty about how eas­i­ly we are influ­enced by the pack­ag­ing and pre­sen­ta­tion of our beer. This week, how­ev­er, a friend tipped us off to a piece of research from 2004 which sug­gests we’re not being entire­ly irra­tional.

The exper­i­ment showed that peo­ple actu­al­ly had a stronger plea­sur­able reac­tion to a soft drink when they were cued up to expect one brand or anoth­er, and pre­sent­ed with pack­ag­ing.

Test sub­jects were giv­en Coke and Pep­si with­out being told which brand was which. These drinks are chem­i­cal­ly almost iden­ti­cal, as Samuel McClure points out. With no brand­ing to refer to, the sub­jects showed about the same degree of “neur­al response” in the “ven­tro­me­di­al pre­frontal cor­tex” in both cas­es. Then, when they were told which brand was which (when they were “brand cued”) they not only stat­ed a pref­er­ence for one over the oth­er, but actu­al­ly, mea­sur­ably enjoyed it more.

So, maybe when we get all excit­ed by the nice label on a bot­tle of beer, and the pret­ty glass it’s served in, and the qual­i­ty of the head on the beer – stuff that shouldn’t real­ly mat­ter, but does to us – we have a sim­i­lar chem­i­cal-elec­tri­cal reac­tion?

We’re not sci­en­tists. If any­one would like to cor­rect or elab­o­rate on our prim­i­tive under­stand­ing of what this research means, go for it!

Beer science – the answers

bunsenandbeaker.jpgWe asked some of our brainy friends to answer a few ques­tions about the sci­ence of beer. Tom was the first to respond. He’s a sta­tis­ti­cal genius, obsessed with lasers, and has stud­ied sci­ence at Cam­bridge and Impe­r­i­al Col­lege. His answers, with lots of dis­claimers about how he’s not a chemist and wouldn’t want any of this to end up on the Nation­al Cur­ricu­lum, are below.

1. Tom isn’t sure what to make of the idea that a huge head on your beer will cause the hop oils to migrate and ruin the flavour. He says:

Hop oils are volatile organ­ic com­pounds, with the ‘volatile’ indi­cat­ing that they like to evap­o­rate. The evap­o­ra­tion of hop oils is not, how­ev­er, nec­es­sar­i­ly a bad thing. Aro­ma being a com­po­nent of flavour, you would be left with lit­tle from the hops oth­er than bit­ter­ness if they did not do so.

I’m puz­zled by the word ‘migrate’. To me this would sug­gest a slow process (per­haps dif­fu­sion of the hop oils along the bound­aries of the cel­lu­lar struc­ture formed by the head) but this would then be imped­ed by the pres­ence of a larg­er head. A more log­i­cal argu­ment would seem to me to be that the hop oils dif­fuse into bub­bles form­ing in the body of the beer, and that tur­bu­lence caused in care­less pour­ing would lead to a large num­ber of these form­ing at the begin­ning. Once these bub­bles burst, the beer would have a low­er lev­el of hop oils than if the beer had been poured care­ful­ly, so affect­ing the flavour. The prob­lem would then be not so much the pres­ence of a large head than the *loss* of the head that neg­a­tive­ly affects the flavour.

More gen­er­al­ly, I would expect tem­per­a­ture to have a greater effect on the evap­o­ra­tion of hop oils, which is why it might be a good idea to drink beer a bit warmer, and yet anoth­er rea­son (if one were need­ed) not to go near Car­ling Extra Cold.

2. Tom thinks clear bot­tles are a bad idea.

This one I can believe, since many com­pounds are pho­tore­ac­tive. The break­down of organ­ic com­pounds by expo­sure to light sounds per­fect­ly rea­son­able. Think of it as sun­burn for beer.

3. Tom thinks beer with arti­fi­cial­ly added car­bon diox­ide might well taste dif­fer­ent to nat­u­ral­ly car­bon­at­ed beer.

Inter­est­ing. Car­bon diox­ide, when dis­solved in water, forms an equi­lib­ri­um with car­bon­ic acid (H2CO3) formed, if it is not obvi­ous, from water and car­bon diox­ide. The equi­lib­ri­um is formed slow­ly how­ev­er, so arti­fi­cial­ly car­bon­at­ed beer may con­tain high­er lev­els of dis­solved car­bon diox­ide and low­er car­bon­ic acid than the equi­lib­ri­um, so depend­ing how soon after car­bon­a­tion the beer was drunk it may have a low­er acid­i­ty than beer with nat­u­ral­ly pro­duced car­bon diox­ide.