There is a good deal of misinformation and mis-impression about the term "Lager." Some of it comes from often erroneous assumptions on the parts of brewers, and some of it comes from the actual ambiguity of the term and process of making Lager beers or Lagering. For a simple definition, we can say a Lager beer is one fermented by any of the group of beer yeasts that functions optimally at temperatures as low as the low 40's and as high as the low 60's.

Now let's look at Lager in greater depth. The first of those issues seems to be the result of the popularization of the use of the word "Lager" in conjunction with the image of mass produced fizzy yellow beers. This common association is the product of advertising and marketing. We have for many decades been conditioned to think "fizzy yellow" and "lager" by the preponderance of print and video advertisements from the mega breweries, who commonly include tag lines such as "one of the world's finest lagers", or "the world's favorite lagered beer". It is entirely understandable that after a period of time, most people have come to equate the subject beers (fizzy yellow) to the term "lager". It follows that it is completely logical that most of us begin the hobby of home brewing armed with this assumption. Let's quickly debunk the "fizzy yellow beer" theory. A fizzy yellow beer can be a lager, but a lager does not have to be fizzy and yellow. Every color of beer made as an ale has a lager counterpart. They may often be hopped differently or otherwise exhibit different flavor characteristics for reasons we will discuss, but beer color in no way defines either ales or lagers.

The second point, the ambiguity of the term and process called "lager" is one that can not be clarified to the point of a concise definition. The fact that many modern dictionaries simply define the word as, "Lager (noun): beer", is either an indication of how effective modern mega-breweries have been, or possibly an admission of defeat due to the actual complexity of the word. Authors of books on beer and brewing processes even take somewhat different stances on the term. Some take a very basic traditional view that essentially defines lagering simply as cold aging. Some extend that to also require at least a partial period of cool fermentation following a warm start. Others maintain that a truly lagered beer must be fermented using specific strains of yeast that function at temperatures below 55 degrees F and never be held above that. The common feature is the exposure of the beer to cool or cold during at least some of the yeast's cycle of activity. If these views seem confusing ... well, they are until you understand why all of them are historically correct. We'll explain.

We know as brewers we must think about what we do using logic and reason. We also find that we must view the history of fermented beverages the same way. Types and styles of beverages, and methods of brewing were at one time dictated solely by indigenously available materials and conditions. Brewing beer in a location with some level of naturally cool or cold ambient conditions required yeast that could withstand those conditions. This is not to say brewers of the day consciously chose a yeast. Prior to the mid 19th century the vital role of yeast was very misunderstood. Yeast, as a residual product of fermentation was seen as just an unfortunate occurance that needed to be removed from the beer. The fact that beer was produced as successfully as it was indicated a skill developed strictly through observation and repetition. Palatable beers produced in cold climates naturally evolved as fermentations based on yeasts that were cold tolerant (lager type), during main fermentation and/or conditioning. At that point, an understanding of the science of brewing was very incomplete.

Through the work of Louis Pasteur and his predecessors, the understanding of yeast's role was finally realized. This previous yeast "nuisance" could now be studied and exploited for the betterment of beer. And not only was it now possible to differentiate between yeast and bacteria, but it became possible to identify differences between families of yeast, allowing isolation of brewing yeast and the removal of other yeasts. For the first time, pure populations of beer yeast could be propagated, making reproducible and clean beers a scientific reality rather than an matter of chance. This of course was also a breakthrough because it paved the way for studying and understanding the differences between beer yeasts. Knowing they were working with pure beer yeast allowed research on how individual beer yeasts reacted differently to the presence of various sugars and environmental conditions, and the subtle flavor differences produced during a specific yeast's life cycle. From that study came recognition of the presence of two distinct species of beer yeast with distinct characteristics that we commonly refer to as "ale" and "lager" yeasts.

Since we are proponents of the practice of comparing and contrasting as a means of qualifying and quantifying differences within any of the beer component groups... we should do that here regarding yeast before continuing this brief discussion of lagering. Ale and lager yeasts share much more than they differ. Basic conditions necessary to support life, and the progression from an aerobic phase to an anerobic phase are identical. The major differences can be simplified and categorized as 1. temperature tolerance, 2. general attenuation (sugar conversion) tendencies, and 3. by-product production.

Lager yeasts tolerate and work optimally at lower temperatures than ale yeasts. Depending on particular strain, lager yeasts may do their best work at temperatures as low as 40 degrees F. Some will be at their best closer to the upper range of lager happiness, near 60 degrees F. It is important to note that "optimum" temperature for any particular ale or lager strain is not where it is going to ferment most rapidly necessarily, but rather where it produces the flavor characteristics desired. We must also recognize that any yeast will work more slowly as the temperature decreases, until ultimately the temperature has dropped to the point to cause that particular strain to become dormant. So, regarding temperature we can say all yeasts work more slowly as temperature drops, but lager yeasts will continue to function after ale yeasts have gone dormant, and may even do their best work, albeit slowly.

Attenuation, or the reduction of sugars in malt to CO2 and alcohol, can vary greatly from yeast to yeast. While there is a broad range of attenuation potential across the yeast spectrum, lager yeasts in general are more attenuative than ale yeasts. That means that while a specific ale yeast may attenuate (reduce sugars) further than a few of the lager yeasts, on the whole lager yeasts as a group are more attenuative. That explains why in most cases lager beers have drier finishes (or are less sweet) than most ales. The more the available sugars ar converted, the drier the finish on the palate.

Yeast by-products are important flavor contributors. Most of you will recall a conversation you've had at some point regarding the virtues of liquid yeast. The fact that specific yeasts create specific flavors via production of specific esters and alcohols means yeast can be a huge flavoring ingredient. Likewise, a yeast that produces less of any of these flavor contributors must still be considered a huge flavoring ingredient for what it does not create. If that sounds contradictory on the surface, think about it for a second. Many of you have heard our speech regarding beer flavor being a delicate balance, and been advised to think of flavor components as being on either side of a beam balance scale. If something on one side of the balance is reduced, the overall intensity of flavors on that side are reduced. At that same time on the other side of the balance something will appear to have gotten stronger or heavier. Just like a balance scale... remove something from one side and it rises while the other side of the balance falls. In the case of lager vs. ale yeast, it is a matter of less being more. Lager yeasts and cooler fermentations produce less and fewer Esters, which are organic compounds that generally have distinctive "fruity" type aromas. While often desireable in an ale flavor profile, the absence of esters in lagers allow for more of the clean malt and hop flavors and aromas to show through in the beers profile. That beer would also exhibit a cleaner crisper finish with less aftertaste. Another aspect of the cooler lager fermentation is the fact that lower temperatures suppress the growth of bacteria and most wild yeasts (the same concept for storing food in refrigerators). In beer, the suppression of wild contributors means keeping their flavor by-products out of the beer... and again that translates into cleaner tasting beer. In fact in pre- Pasteur times when lagers first began to gain popularity, that lack of bacterial influence may have helped them gain popularity and begin the lager revolution.

Now that we've briefly covered the topic of what a lager is and how it differs from ale, we can move on to how to do it. Obviously it requires some degree of temperature control. At this time of year that can be something called the garage... you know, that place with a walk path between the boxes full of old clothes, toys, and the Christmas decorations you always talk about putting away until July when you decide it's already over half way to next Christmas... so why bother? That garage. During the cool Winter months a garage or a storage closet off of a patio or balcony can provide just the place for reasonably constant cool temperatures a lager yeast would love. Though at night the outside air temperature may get colder, chances are the average temperature of the garage will remain in the mid to upper 50's. And even if the air temperature rises during the day the fermenter full of beer will change temperature pretty slowly, thus providing a pretty stable environment for your lager yeast. At the lower temperatures your beer will likely need a good 3 to 4 weeks to ferment out completely, and you'll likely want to let it warm up inside the house for a couple days before you bottle, just to make sure it's real done. But like any fermentation, you have to monitor activity and get a feel for its cycle, and are advised to use hydrometer readings to help make the decision to bottle. After bottling, you can continue to cold age the beer by taking it back to the garage and allowing extra time for carbonation to form, or you can let it carbonate inside the house. If you choose the cold aging, you will probably see a cleaner clearer looking beer as the reward for your patience.

The other way to make lagers is to have a spare refrigerator, or a small chest freezer (usually more energy efficient than a refrigerator) outfitted with a "slave" temperature controller. If you have one of these luxuries you can choose a particular temperature and hold it more uniformly. While it is not necessarily going to produce a better beer than the garage method, it would allow you to make lagers at any time of the year. Using the slave temperature controller would even allow you to set the refrigeration unit to perfect ale temperatures during warmer Summer months. That provides much greater flexibility throughout the year, and for those who find Summer brewing problematic provides a perfect solution. See the "blatant self serving advertisement" later in the issue.

Whether you take advantage of the cool weather or use controlled refrigeration to make a lager, we think you'll find it an enjoyable experience. And for some of you with whom we've had discussions regarding flavors and aftertastes in your beer that you don't necessarily desire... well, lagering may be just the solution you've been looking for. Talk with us about your individual location and temperature conditions and we can help customize the process that will make your lagering experience a fruitful one. Using the cool weather to try it out can tell you if you'd like to make the investment into the controlled refrigeration approach.

A final word of advice... After you get your lager started and while it ferments, get an ale going inside the house. Having a beer in the "pipeline" that will be ready to drink sooner than your lager will help you have the patience to let the lager move along at its pace. Don't rush it, but for goodness sake don't run out of beer!