Separating the ales from the lagers

A breakdown of what makes a different style

Of beer’s four building blocks yeast is the Rodney Dangerfield of the bunch — it gets no respect. All the attention goes to the other three: barley hops and water. For proof of this one need look no further than beer commercials in which breweries go on and on about how special their water is show fields of their precious barley and even boast about their imported hops. Have you ever seen a slurry of yeast in a commercial? No.

It’s okay yeast is used to this lack of respect it has been happening since beer was invented. The Reinheitsgebot or the Bavarian Purity Law punctuates this even further. The 1516 Bavarian regulation lists that beer must be made only from water barley and hops — absolutely no mention is made of yeast whatsoever.

Yeast didn’t start to get noticed until the 1830s when Cagniard de la Tour and several contemporaries discovered yeast’s role in beer fermentation. Don’t feel bad for yeast though because it has a fantastic life. In its life cycle in beer all yeast does is propagate and masticate to orgiastic and gluttonous levels until its partied-out carcass explodes.

It is the waste products from this funny fungus that make beer unique. Think of it as a happy Pac-Man gorging on sugar farting out CO2 and peeing out alcohol on its way.

It is when yeast parties in the fermentation cycle of beer that defines whether a beer is ale or a lager.

The ale family is the oldest of the two beer families and has 50-plus styles — from American ambers to German wheat ales. Ale yeasts like to work at warmer temperatures require less refrigeration are quicker to ferment and are the less expensive of the two families to brew. “Top fermenting” describes when the yeast has its fun and explodes in ales. The spent cells then drop through the beer adding what brewers call “fruity esters” which make ales special. Style-specific ale yeast strains are chosen as they add certain esters — from big and fruity to soft and spicy — to your brew. It doesn’t happen often enough but ales should be served cool (not cold) slightly warmer than fridge temperature. (Some of the styles to look for in the ale family: IPAs lambics and porters).

Lager yeasts are the newest kids to the party — they have only been around since 1883 when the Carlsberg brewery first isolated lager yeast. Lagers use “bottom-fermenting” yeasts that sink and ferment at the bottom. Lagers account for 90 per cent of all beer consumed globally.

The term lager comes from the German word “lagern” meaning “to store.” Although not recommended ales can be brewed in as little as seven days while lagers need a longer process sometimes months fermenting at temperatures in the seven to 15 C range temperatures that make ale yeasts go dormant.

Brewers found that the beers stored and fermented cold left a much clearer beer free from turbidity with none of the esters prevalent in ales. The yeast in lagers does not leave as big a flavour impact; it creates beers with a clearer smoother crisper taste. Lagers should be served cold. Some of the styles to look for in the family: Pilsners Oktoberfests and doppelbocks.