This is the first section of a three-part article on lagering:
- Chapter 1 - "Lager": What is Lagering
- Chapter 2 - "Lager": How to Lager
- Chapter 3 - "Lager": Advanced Tips
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, there's a very good chance that you're 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.
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 they're 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? That's not just because you're getting sentimental. Its because you've basically been lagering the beer in your fridge the whole time — long enough to reap some of the benefits before its gone.
Try this at home: Go out and buy two six-packs of a good quality ale. Store one six pack somewhere relatively cool (around 60F), like your basement, where it'll stay fresh for a while. Store the second six-pack somewhere much colder — as close as you can get to freezing, without quite getting there. (Probably the very back of your fridge.)
Leave both six-packs alone for a few weeks, and then do a taste comparison between the two. Odds are, you'll be able to see and taste a real difference, with the advantage going to the cold-stored beer.
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 don't 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 don't. (With some important exceptions: see the discussion of Diacetyl Rest, in the next chapter.)
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 doesn't 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 don't 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.
Bock - Traditional Bock beers were actually brewed as ales for centuries, before the style evolved to take advantage of lager techniques in the 17th century. They are typically a strong beer (6% - 8% by vol), with a sweet, malty body, and very little hop character (20 - 30 IBUs).
Doppelbock - A darker, more intense version of the Bock style, usually with a less-pronounced malt flavor, and more hops.
Rich German malt aroma. A light to moderate toasted malt aroma is often present. Clean lager aroma with no fruity esters or diacetyl. No hop aroma.
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.
Alt Bier - Some claim that "alt" ("old") refers to the fact that by the time this ale is served, it's been cold-stored for months. On the other hand, this is a top-brewed, cold-stored ale that had been around for centuries, but faded as bottom-brewed lagers gained popularity in the 16th century, so others feel that the name refers to a beer made in the "old" style. Either way, this is a crisp, clean ale that keeps a brewing tradition alive.
Kölsch - Like champagne, this beer can only legally be called Kölsch if it's been made in a tightly-defined region, but the style is classic -- light-bodied and clean, but still bringing the fruity character of an ale.
Want a great way to lager your beer safely, and save space in your cooler? These keg lids let you pop an airlock on top of a corny keg, and voila! You've got an unbreakable lagering vessel that gives you room to lager even more beer!
Next: Chapter 2 - How to Lager