Saturday, 27 October 2012

On Yeast - or - Yeast Is Like Light*

As I sit here sipping my way through a bottle of Badger The Wandering Woodwose (8%abv), I'm immediately struck by two things. The first is what a lightweight I've become of late, and how I can feel the effects of the alcohol after barely a few sips. The second is that even though this is a substantial departure for Badger - 8%abv, bottle-conditioned - it's immediately identifiable as a Badger beer, mainly down to the house yeast character. There's something classically British (or is it English?) about the soft, fruity, ripe-melon sweetness in this beer that isn't down to the malt, hops, flavour additions (a favourite of Badger's) or anything notable about the water profile. It's the yeast, stupid.

Yeast is so much the underplayed ingredient in beer that one rarely hears it talked about, even in the uber-geek recesses of the beer blogosphere, and yet ask any brewer if they would switch yeast strains, and you'll receive the sort of "you don't get it, do you?" look and shake of the head usually reserved for the feeble-minded.

The reason for this is that no matter how badly behaved a particular strain of yeast is - and let's for the moment just restrict ourselves to the seemingly endless variations of s. cerevisiae - it is absolutely fundamental to the character of a beer. I know of a brewer at a particularly successful brewery who feels that if he leaves the building for longer than a weekend, the yeast can sense that it's their chance to misbehave, and things go awry. But rather than ditch and switch, they soldier on because nothing else tastes quite the same as their own house strain.

And it works the other way too - I've done guest brews at a brewery where when I asked what their house strain was (or what it started as - yeasts will subtly mutate over time), I was told that the brewer didn't know. And another brewery who need to let the yeast run away with itself and ferment warmer than might be conventionally expected, otherwise the beers don't have the particular character that they are famed for. Or the brewery that uses the waste yeast slurry from another brewery. And for the avoidance of doubt, all the above examples are top-tier UK breweries, not madmen making ropey beer in unsanitary conditions.

A few years ago, I stayed in post-festival Cannes for a couple of days. As someone who is interested in art, I remember thinking that all the tales about the intensity of the sunlight there turned out to be true. The light there gave your vision a peculiarly heightened quality that was hard to define, and yet also unmistakable in whole swathe of 20th century art. Just as the quality of light and how it affects what you perceive is important to an artist (go and have a look at Monet's Haystacks for an example of this), so the way a yeast behaves is key to how a brewer makes a beer, and how that beer is perceived by the drinker.

As I say, I've become a bit of a lightweight lately.

*with apologies to Gabriel Garcia Marquez

8 comments:

  1. When Wychwood Goliath was contract-brewed by Robinson's at Stockport, it was identifiably a Robinson's beer and to my mind all the better for it.

    And everything brewed at Whitbread's Cheltenham brewery had a distinctive full mouthfeel.

    But to what extent was that down to the yeast, as opposed to the nature of the fermentation vessels?

    ReplyDelete
    Replies
    1. I think that vessel dynamics certainly play a part, but my hunch is that within the usual parameters of a conventional modern brewery (that's to say, the difference between Wychwood and Robinson's), this is a very small part of the character. Perhaps someone with actual knowledge of the subject might like to chime in?!

      Delete
  2. With the rise of the juggernaut IPA we placed hops into the category of all important. It seems all too easy to forget the subtle and on occasion dramatic impact that yeast can have in a beer. When I look at the difference between Bell's Brewing and Arcadia Brewing (the breweries closest to my home), both have distintive house strains. Bell's strain tends to be a bit more subtle, while the ringwood yeast that Arcadia uses tends to have a dramatic affect on the beer. But neither would be who they are without their house strains.

    ReplyDelete
  3. Well put Zak. Some departures from the fruity melon type of English top-ferment taste include, IMO, a beer like cask or keg Old Speckled Hen - that style has a bready, almost bitter yeast quality, similar to the typical Belgian ale yeast flavour IMO again. Some other English beers, especially Southern ones, have it too.

    Of course, temperature and yeast are intertwined, as you noted.

    Whatever the yeast type, there can be too much of a good thing. I know that real ale, indeed keg and bottled or canned beer, can taste yeasty even though looking clear; still, my experience is that real ale should be served well-fined to get the most of the yeast cake on the bottom while contributing to the proper yeast-malt-hops balance that makes the essential character of the beer.

    A cloudy pint, not generally an issue in the U.K. but frequently encountered in North America, can taste too strongly of yeast. Too much yeast, and the balance of the beer is gone. Despite this, opaque ales are commonly encountered here for cask beer. Even non-cask draft often is dispensed fairly cloudy. Clearly people like it, so fair enough, but I am old-school on this.

    Gary

    P.S. Hefes and kellers and so forth are well-established exceptions and fair enough again, but I wouldn't extend that approach to English-style brewing.

    ReplyDelete
    Replies
    1. The thing is Gary that often the haze you get in American (and unfortunately NZ) beers isn't just yeast but all sorts of other things. Dry hop hazes in particular, but also protein haze from the mash tun, can leave all sorts of tannic and phenol characters in the beer that make them harsh and less drinkable. The market unfortunately seems to just think this is a sign of hoppy character.

      Delete
  4. Very well said, yeast is incredibly important. As a lover of characterful fermentation I'm all for people 'getting it' .
    As stated above house character does extend further than just yeast though. Fermentor shape, brewhouse design, water profile all play a part. However yeast is definitely the most important. I usually use one of the two Fullers derived yeasts for my brewing, probably the most identifiable English yeast strain. However right now I am experimenting with the Ringwood strain. it's pretty awesome as well.

    ReplyDelete
  5. Totally agree.

    ReplyDelete

Sorry about the word verification - the blog was getting spammed to bits.