Lager: I Do Not Think That Word Means What You Think It Means
You keep saying that. I do not think that word means what you think it means. — Inigo Montoya
Believe it or not, lager is probably one of the most misunderstood (and misused) terms that we use when we talk about beer. Even if you think you know what it means, theres a very good chance that youre actually using the term incorrectly — and missing out on a technique that can improve all the beer you make.
In this article, we are going to start by exploring some of those misconceptions, but then were going to dive into exactly how lagering works, and how you can take advantage of it for yourself to make great beer.
Misconception #1:Lager and Ale Have Opposite Meanings
The original German word, lagern, only refers to the process of cold storage, and — contrary to common belief — you can productively lager any beer, even a standard ale. In fact, many breweries lager their beers, whether theyre making a pale ale or a pilsener.
What does lagering do to a beer?
A well-lagered beer is not only going to be clearer (and therefore cleaner-tasting). Its also going to have a more developed set of flavors showing through. You know how if you savor a keg for a few weeks, that last beer looks and tastes so much better than the first one? Thats not just because youre getting sentimental. Its because youve basically been lagering the beer in your fridge the whole time — long enough to reap some of the benefits before its gone.
How does lagering work?
There are two important processes at work when a beer is in long-term cold-storage:
- Precipitation: Take a certain amount of liquid, warm it up, and you can obviously dissolve more solids into that same volume. Take that same warm liquid, and cool it down, and the amount of dissolved solids that it can contain will decrease. Those solids will precipitate, or re-solidify and fall to the bottom of your storage container. (The simplest version of this process is what we all know as cold-crashing.)
- Aging: All the chemical reactions going on in your beer — good or bad — take place much more slowly in the cold. As it happens, though, most of the processes you dont want are slowed down more. An extended period of cold storage builds up the benefits that you do want, with less of the effects that you dont. (With some important exceptions: see the discussion of Diacetyl Rest, in the next chapter.)
Misconception #2:Lager = Bottom-fermentation
Lagers are typically defined as bottom-fermented beers. While this is usually true, its not necessarily true — cold storage was used to make beer for centuries before the cultivation of bottom-fermenting yeasts.
As a matter of fact, it was the tradition of cold-storage that led to bottom-fermenting — centuries of lagering brought about a new strain of yeast, one that thrives at colder temperatures (saccharomyces pastorianus). Since these yeasts obviously work much better cold, its only natural that the process and the product became so tightly linked.
Beyond a preference for colder temperature, lager yeasts are different from traditional ale yeasts in a few important ways:
- Bottom-fermentation: Obviously, lager yeasts tend to concentrate at the bottom of the wort during fermentation, rather than the top. While this doesnt have much practical significance, it does help make clear siphon transfers.
- Higher attenuation: Most lager yeasts are able to convert a broader range of sugars than the typical ale yeast, so they generally produce a clearer, less fruity beer, with a slightly higher alcohol content.
- Undesirable by-products: Lager yeasts are also more liable to generate some unwanted compounds, especially sulfur and diacetyl. There are specific steps that can minimize these effects, though, which we will get into in the next section.
Misconception #3: Lager = Pilsener
Even though light-bodied and crisp styles — especially pilseners — have come to represent a lager, you dont want to overlook a wide range of excellent, distinctive lager beers. The world of lager beers encompasses many of the very darkest styles that you can find, as well as clean, well-balanced ambers.
We should also keep in mind the rich history of bottom-brewed, cold-stored beers that actually helped lead to the development of the modern lager style. These ales are all traditionally lagered for long periods, and as a result combine some of the best characteristics of traditional lagers and ales.