What’s the difference between ale and lager? I will attempt to answer this common and age-old question. Here goes! (It’s okay to take a beer break somewhere in the middle)

It all starts with a simple one-celled creature of the fungus family, saccharomyces cerevisiae (Ale Yeast– see, um, photo at right). This little critter has been around for a long time and has spawned many different variations, all designed to multiply and eat the fermentable sugars in brewers wort; then expel ethanol (alcohol) and burp some CO2. Ale yeast are called “top fermenting” yeast, because they tend to work from the top down in the fermenter. Ale yeast also like to work where it’s warm, around 60-70 degrees F. This last point is the key to why ales were the first beers produced. Beer was first thought to have been brewed 6000 years ago in the warm climbs of Sumeria. Ale critters love to work in that climate, so ale was what was for supper. Ale continued to be what beer was until thousands of years later.

Ales typically deliver a certain fruitiness that can taste like pear, apricot or even banana. These fruity flavors are a product of ester production during fermentation at higher temperatures, but this is where ale yeast does its best work. As with all beers, balanced flavors are key. Nobody wants to drink banana beer or green apple beer. Fruity flavors are appropriate when they are just lying on a thin layer of complexity in the beer, letting the malt and hops take center stage.

Most of today’s craft brews are ales, which require less time and investment to produce. The vast variety of specialty ale yeast is overwhelming, each delivering a completely different flavor profile. For instance, a brewer cannot capture the essential flavors of Bavarian weizen, without using the proper yeast strain. Brewers will identify certain strains by number (like 1056) or we may use a nickname like “pacman” for a certain strain.

Lager yeast (saccharomyces uvarum) are more sophisticated creatures. They perform the same basic functions as ale yeast but they like to work in colder climates, and they can be finicky. They are slow workers, but that’s because they are perfectionists. They do their work near the bottom of the fermenter. They don’t make a scene like those un-sophisticated ale yeasts, spitting and spouting CO2 and foam. They are much understated, expelling just a thin blanket of foam on top while fermenting. Historically, lager yeast worked best in the colder parts of the brewing world, like Germany and the Czech Republic. Naturally, these yeasts became predominant in those areas. At these colder temperatures, ale yeast would just get lazy and sleepy, leaving nasty bacteria in charge of the fermentation with nasty results, Yuk!

The world lager is the German word for “storing” something. In this case it refers to the typical resting or “lagering” period for this type of beer. Lager yeast takes longer to work. They also have the ability to clean up after themselves, typically re-absorbing many of the sulphury and estery compounds produced during fermentation. Lager yeast can also eat more of the complex sugars that ale yeast cannot, leaving a much cleaner and dryer taste in the finished beer. This happens during a period of aging or “lagering” after fermentation. The fact that lager fermentations can be so clean is the very reason that the Macro brewers use lager yeast to make their flavorless brews. God forbid if something were to add a bit of flavor to the beer!

Don’t fret! There are many great lagers available. Real Czech pilsener is always a good choice. German bock and doppelbock beer are very flavorful lager beers. Many lager yeasts leave their mark. In some lagers, a slight sulphury taste is appropriate. Sometimes a small amount of buttery diacetyl flavor is evident and okay in certain beer. These variations are what keep an otherwise boring yeast strain, interesting.

To really taste the difference, taste a Warsteiner Premium Verum pils. This is a clean lager. You will not taste any hints of fruitiness, but maybe just the slightest sulphury bite. The beer will finish crisp and dry. Next, move on to an Ayinger Brau-weisse (hefeweizen), this is an ale. You cannot help but notice slight hints of banana and clove. These flavors are the result of ale fermentation. The banana flavor comes from esters and the clove comes from phenolics, both fermentation by-products. The wheat can accentuate the clove flavors.

Remember, brewers make wort and yeast make beer — Lager or Ale!

This entry was posted on Wednesday, April 11th, 2007 at 6:18 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.