Beer: The Difference Between Ales and Lagers
Ales, Lagers, What?
When shopping for beer, the terms "ale" and "lager" are often heard, but rarely explained. The small print may denote ale or lager, but what does it mean to the consumer? There will be simple differences in color, taste, alcohol content, and the like. I will explain these later, but first you must understand that these are rooted in hundreds of years of brewing tradition. We can reduce the difference to one word: yeast. This sets off a series of changes in brewing style, taste choices, alcohol content, and much more.
"Lagers" are nearly ubiquitous in most markets nowadays, but most are not good examples of their respective styles. Do not let Budweiser, Miller, Coors, or whichever mainstream brewer that calls their product a lager or ale define those styles; those are mass-produced and designed to be as inoffensive to a novice drinker as possible. More representative lagers and ales will be brewed with more craftsmanship and have more flavor, body, etc.
Ales vs. Beers
We now understand "beer" to refer to all of these fermented barley drinks which include ales and lagers. Originally, however, ale was used as a means to describe a less bitter barley drink than what was being called beer. In fact, it was a term that referred to a drink that didn't have hops or any bittering agents. Beers were the hopped variety that came from outside of England. Since, though, it has come to be a catch-all for all beers brewed with top-fermentation, which all English beers were at that time.. Note: I do not have a British/English bias, we are simply talking about English language terms and they are (not surprisingly) rooted in England.
Ales date back to medieval times in England, when the alcohol in beers and the warm temperatures used in the ale brewing process warded off many pathogens that were killing people en masse.
The definition of ale as we know it was not truly solidified until American homebrewers in the 1980s began dividing all beer recipes into "ale" or "lager" based on their yeast. Before then, there had been significant evolution in the term "ale" and its relationship with beer.
Ales and Top-Fermentation
At this point in time, the main distinguishing factor between ales and lagers is their yeast and thus fermentation method. Ales are brewed with top-fermentation, a much older style of brewing than the lager equivalent.
The fermentation process occurs near the end of the brewing process, after the barley has been malted, mashed, and has hops added. It is at this point that yeast is added to ferment the beer, where alcohol and carbon dioxide are made as well as subtler components that may add flavor, depending on the type of yeast. The carbon dioxide makes the beer carbonated and the alcohol makes it illegal for those under 21.
Top-fermentation, also known as warm-fermentation, is so-named because the yeast's foam rises to the top of the mixture. The brewers' yeast used in ales ferments at relatively high temperatures, which is where we get the second name.
This method can yield higher alcohol levels and since it is not the most efficient at fermenting sugars, ales have the capacity to be sweeter and smoother than lagers.
Lagers and Bottom-Fermentation
Lagers come from a different type of yeast than ales and came about centuries later than ales. The lager yeast strain is a hybrid of two other yeast strains. Some say that the first lagers may have been the product of accident more than anything else. Brewers making beer in cooler conditions did not yet know the science behind fermentation, so they did not know that lager yeasts were fermenting at lower temperatures even when they were attempting to make ales. In the mid 1850s, brewers began using these methods by design and now 9 out of 10 beers consumed in the world are lagers.
Lager yeast ferments at a relatively low temperature and does so slowly. In German, "lager" means storage. The slow fermentation process requires lengthy lagering to finish the brewing process, which takes at least several weeks, in which undesirable flavors and aromas are changed by the yeast. With no foam rising to the top of maturing beer, the style became known as bottom-fermentation. Cold-fermentation, an alternate name for this process, likewise refers to the relative temperatures at which fermentation occurs.
Because of how lengthy and thorough the lagering process is, lagers are generally less complex than ales. This is not a bad thing by any stretch, as complexity is not always better. Lagers are often described a "smooth" or "clean," an effect of the lagering process. Lagers can be broken down into "helles" lagers and "dunkels," meaning light and dark. There are other sub-types, but they start from there.
Presently, most mass-produced beers are lagers and employ adjuncts, usually rice or corn. Rice and corn are cheaper than barley and lighten the body and flavor and can cheaply increase alcohol content. Most beer connoisseurs do not look fondly upon "adjunct lagers," as they generally have little taste and have flooded the market with very similar beers that advertise as if they are not similar. To evaluate lagers, it would be best to try some that are not made with adjuncts.
There can be considerable differences among both ales and lagers, so it is not especially productive to reduce them to particular characteristics. The only consistent difference will be the strain of yeast, though even that line is becoming blurred.
Check the ingredients on both ales and lagers to be sure that adjuncts have not been added to cheapen production and water down flavor. The best lagers will often be crisp, smooth, and simple whether they are light or dark.
Ales can vary even more broadly, from pale ales to stouts. Nonetheless, ales almost always shoot for greater complexity.
Any beer lover will enjoy both styles very much, but experience will help most with learning what to expect from each type of brew.