What's in an Ale?

Let's get away from politics and bars and talk about beer on a purer level today. I want to try to clear up a very simple notion that causes much confusion amongst the casual beer consumer.

What is ale?

I am not a brewer or a microbiologist so, for some, my explanations may be oversimplified and a little unscientific but this isn't a brewing lecture - it is a (overly)simple explanation of beer types.

It's all in the yeast.

Most beer is made with one of two basic yeast types: Top Fermenting Yeast or Ale yeast, or Bottom Fermenting or Lager Yeast. Within these groups there are countless different beer styles but for the purpose of this exercise, I'm going to categorise all beer into one of the above two.

Lager is probably the easiest to understand as there are less commonly available variants to the style. Lager is usually a pale, golden brew fermented with a Bottom Fermenting Yeast which ferments at quite a low temperature (around 6- 9 degrees C.) and is stored (lagered) at around 0 degrees C. for one to three months to condition. The resultant brew should be clear with clean, crisp flavours and is usually served well chilled. There are, of course, variations on this. There are amber lagers, smoked lagers, dark and almost black lagers but all will have a Bottom Fermenting Yeast acting on them at low temperatures. The first single-cell, bottom fermenting yeast was isolated at the Carlsberg brewery in Copenhagen in 1883 by Emil Hansen. Bottom fermenting yeasts are hence known as Saccharomyces Carlsbergensis. Most people don't have a problem identifying a golden lager.

Ale, on the other hand, confuses people. Keeping in mind my oversimplification, all ales are fermented with Top Fermenting Yeasts (Saccaromyces cerevisiae) at a higher temperature of 15-25 degrees C. This type of fermentation produces fruity, spicy flavours and a far more aromatic beer which usually is served a little warmer than lager. Within the broad category of ale there are so many variants (ale,stout,abbey beer, porter, barley wine, red ale , blonde ale etc. etc.) that it is hard to group them together but they all share a common type of yeast. Bare in mind that while each brewer may use their own particular strain of yeast all ale yeasts will be of the same family (Saccaromyces cerevisiae).

So, it's that simple. The basic difference between ale and lager is the type of yeast. We can have pale, blonde ale (Duvel) or we can have dark lager (Budvar Dark). Stout usually uses a Top Fermenting yeast and there are even hybrids like Anchor Steam which uses a Bottom Fermenting yeast but manages to ferment it at the much higher temperatures associated with Top Fermenting.

For those of you still with me at this stage, it wouldn't be right to talk about yeast and fermentation without speaking of Bottle Conditioning . This is the practice of allowing the beer to ferment a second time in the bottle. This produces more alcohol and CO2 ( natural carbonation), preserves the freshness of the beer and produces complex, flowery flavours. It can be achieved by ensuring there is enough yeast in the beer prior to bottling to refermentation or by adding (pitching) fresh yeast to the beer. There may be enough sugars in the beer for refermentation or glucose or a portion of young fermenting beer may be added to feed the yeast. A different yeast may be used in this secondary fermentation than in the primary fermentation. It is usually Top Fermented beers which are bottle conditioned but there are exceptions.

Bottle conditioned beers will always have a sediment in the bottle which, depending on the style of beer and personal taste, will either be swirled into the beer or carefully left in the bottle. Weissbiers and Belgian Wit biers are usually served with the yeast sediment in suspension. Bottle conditioned beers are naturally fizzy as the CO2 produced in refermentation is trapped in the bottle and causes carbonation in the beer. Other beers are bottled under pressure with CO2 'injected' into the bottle. Bottle conditioned beers have more character than filtered, carbonated beers and will mature and develop over years in the bottle much like a fine wine. (Many bottle conditioned beer continue to improve long after their 'Best Before' date has expired)

Despite my oversimplification of beer into two distinct types, defined by yeast, I will also mention Spontaneously Fermented beer. These Belgian artisan beers called Lambics, are fermented by naturally occurring wild yeasts. These yeasts belong to a different family and these beers deserve a post all to themselves.

So there you have it. Ale doesn't mean warm, flat, red, watery tasting beer. But it can do!

Get out there and drink some ale ! It might not be what you thought.

Here's an interesting article by someone who really doesn't agree with my blunt division of beer into two categories .

My last drink was; Nils Oscar India Ale, 33cl, 5.3%abv