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.

The Session: Christmas beer

session-logo-r-sm.jpgThis month’s session is hosted by the Barley Vine, and bloggers were asked in this post here to pick a seasonal beer or two.

We thought we’d bend the rules slightly and pontificate on Christmas / “winter” beers, and possibly get round to drinking one later. It’s not through lack of choice – London’s pubs are full of various seasonal offerings, and at the Pig’s Ear beer festival in Hackney I counted around 50 beers described as “Christmas Ales” from Britain and a dozen or so foreign offerings. It’s just that it’s an interesting topic in its own right: what, if anything, makes a Christmas beer?

In Britain, Christmas ales tend to be dark (but not as dark as porters) and spicy. This no doubt is related to our Christmas foods, which tend to be dark and spicy. The spices used tend to be cinnamon, cloves and nutmeg — all ingredients that shout “Christmas” at you. Unfortunately, these spices are quite difficult to get right. Too much and you end up with quite astringent flavours and “the wrong kind” of bitterness; too little and you may as well have not bothered — it’s just a gimmick to make the beer sound attractive. It’s quite rare to get a beer where you can taste the spice BUT without it being overpowering — like Dorset’s Advent-ageous which we tried at the Pig’s Ear festival.

Interestingly, Christmas ales in Britain are often not that strong. While some brewers see it as an excuse to whack up the malt and therefore the strength, most seem to stick to around the 5% mark. The evidence for this comes from the programme of the Pig’s Ear Beer festival, where there are plenty on offer at under 5%. Probably a good job given the amount we drink at Christmas in this country…

Belgian brewers are not ones for being constrained by styles or rules, and this applies to Christmas beers as well. Some are light, some are dark, but from the couple we’ve had, they don’t strike us as being more spicy than usual. They do tend to be stronger than usual though — e.g. Dolle Brouwers “Stille Nacht” at 12% (a nice drop, from what we remember, but that was a while back).

How about Christmas wheat beers? We’re not experts on the German brewing scene, but it was interesting to discover last time we were there that several breweries produce winter wheatbeers. We had an excellent beer called “Schneewaltzer” from the Herrnbrau brewery in Ingolstadt, described as a “Winterweisse”. It tasted incredibly Christmassy, even though we were drinking it in April… but then it’s not that surprising, given that one of the dominant flavours of many German wheatbeers is cloves, which we Brits always associate with Christmas.

belenos.jpgBut back to the Session topic! We tried a Christmas beer from Spain: Belenos de Navidá. I spotted it in El Corte Ingles, the legendary department store where you can get everything, including decent beer. It’s 9%, made in the Asturias region by “Exclusivas Tormas”, who seem to mostly be an importer / distributor. It says “we made this beer to celebrate Christmas 2006” in strange Castillian (archaic? regional? I wouldn’t dare say). I wonder whether that means they made it around Christmas 2006, or to sell over Christmas 2006? It’s best before November 2008, at any rate.

There’s no other information on the label. Is it bottle-conditioned, top or bottom fermented? The only source of further information on the internet is a web-forum about Spanish beer, from which I’ve been able to ascertain that:

  1. you can get it on tap in Oviedo (Asturias) but not many other places, though I don’t know if that would be the same as this “Christmas” beer;
  2. there’s rumours that it’s made in Belgium and only bottled in the Asturias, although these rumours are contested; and
  3. it reminds subscribers of this forum of a Belgium triple.

It pours a nice red colour and definitely has yeast suspended in it. It does indeed taste Belgium abbey / trappist through and through — good body, toffee-apple flavour, mild zestiness and spiciness. Extremely drinkable for its 9% and quite possibly the best beer in Spain.

Not that that’s saying much.

In conclusion, possibly the only thing that links Christmas beers is that they are an opportunity for brewers across the world to try something different, to experiment with their recipes and make something special.

Brocket's Beer

brocketsbeer.jpgThe Independent’s list of the 50 best beers in the UK included one brewed for Lord Brocket.

Lord Brocket is an old Etonian who is (just about) famous for (a) having been in prison and (b) appearing on the appalling reality show “I’m a Celebrity, Get Me Out of Here!”

He now has a side-line selling Brocket’s Bacon, Brocket’s Bangers and so on.

I wonder which marketing genius thought that having a minor celebrity mugging on the label would make people want to drink Brocket’s Beer? I mean, the beer itself might be perfectly nice, but, well, just look at him! He’s grinning like a maniac and wearing a tweed jacket. We should probably be grateful he hasn’t got his thumbs up, I suppose.

Still, it could be worse. At least no-one is expecting us to buy Jeffrey Archer IPA or Jonathan Aitken Stout. Not yet, anyway.

50 best beers

Today’s Independent has an article on the 50 best beers available in the UK.  It’s a surprisingly decent piece, although a couple of the choices are a bit odd (as you’d expect). Estrella Damm…? Marks and Spencer’s Italian lager!? And Badger bloody Golden Glory, which I think is disgusting.

I was pleased to see the CO-OP’s Strong Ale in the list. It’s a guilty pleasure of mine: full of dodgy caramel, clear bottle, pasteurised, filtered. But it’s very tasty anyway — sweet and malty, somewhat like a strong mild.

Their number one? St Peter’s IPA, which I’ve never had. I’ll have to get my hands on some and give it a go.