Jeff Flowers on September 7, 2016 13 Comments Though there are any number of different types of beer, with ale and lagers the most common varieties with many sub-types within each of those varieties, it’s easy to find a beer to please virtually any palate. But, what’s the difference between these two types of beer, and how does it affect the finished product and your overall experience? Though many people believe it to be no more than a difference of yeast, there is actually a wide range of factors that can impact your beer’s final quality, clarity and flavor. Each of these aspects, including the yeast, can make a big difference on how the different styles turn out in the end. What’s the Difference Between Ale and Lager? From mega-brewery billionaire businesses to your basement brew-setup, there are any number of differences. Knowing how those differences can impact your beer is the first step to understanding how the complexity of quality in the final beer is achieved. Let’s take a closer look at some basic differences between ales and lagers, to help give you a better understanding of how they are each unique, as well as help guide you through the brewing process. Yeast Ask most beer aficionados what the differences is between ale and lager, and you’ll get a simple answer: the yeast. Though this statement is true on its face, it’s actually a bit more complicated than that. It’s commonly understood by many beer enthusiasts that ale uses a top-fermenting yeast and lager uses a bottom-fermenting yeast. Both of these varieties actually disperse throughout the entire fermentation vessel while brewing is underway, but it will be more apparent at the top or bottom during particular stages of the fermentation process. But what else differs between these two common yeast types? Here’s a quick rundown: Ale: Ale is fermented using Saccharomyces cerevisia, a very common yeast type used for a number of different applications, including wine and bread making. It’s a hardy variety that deals better with varying environments, whether it’s a wider range of temperature, a higher alcohol content or many other changes. It’s the original yeast of civilizations and has been found across the entire world, including Antarctica. It’s referred to as a top-fermenting yeast because it will first rise to the top and then will sink to the bottom of the brewing vessel when fermentation is ending. This quality also makes it very easy to harvest the yeast without disturbing the process. In historical cultures where bread making was developed alongside the brewing industry, this would make it easy to use the excess yeast at the top of the vessel for leavening bread. The fast action of this yeast species brews the ale in as short a time as a week, with the yeast products floating to the top due to the increased motion within the fermentation vessel. Lager: Lager, on the other hand, is fermented using Saccharomyces uvarum. It was first used for brewing in Bavaria in the Renaissance, one of the first species to hitch a ride from the American continents to Europe during the discovery and exploration of the western hemisphere. This yeast isn’t so much bottom fermenting as much as that it doesn’t rise to the top as an ale yeast will before settling to the bottom as fermentation winds down. Because the yeast didn’t really show up at the top of the fermentation vessel, it was probably assumed to be bottom fermenting instead, as early fermentation vessels were constructed of materials that made it difficult to see the bottom of the vessel. Compared to ale yeast, it is a much more fragile yeast, which requires more specific conditions to thrive. However, this means it can produce different outcomes than ale yeast. This fragility means the yeast can’t sporulate, or form a cyst of a few cells with a protective wall at cold temperatures, which means this yeast can remain active at temperatures below 39°F. It also attenuates sugars more slowly, causing the brewing process to move more slowly. It has a lower tolerance to alcohol and has the ability to ferment mebilose, a sugar that is not fermented by top-fermenting yeasts. These last three features allow more sugar to remain in the mix, creating a smoother, sweeter beer. Alcohol Content No matter what type of beer it is, the yeast will directly impact the overall alcohol content, our second area of interest. Because ale yeast is much hardier in higher-alcohol environments, it will survive into higher levels of alcohol, causing ales to have a higher alcohol content, in a general sense. By comparison, the slower, more fragile lager yeast generates less alcohol because it can’t survive beyond that lower alcohol content, causing lagers to generally have a lower alcohol content. Temperature of Fermentation Another area of distinction between these two varieties is the temperature at which they are fermented. Most yeasts will die off at temperatures below 104°F and will sporulate and cease to act at temperatures below 58°F. Top-brewing ales tend to be brewed at higher temperatures, usually between 60-80°F with some unusual varieties going as high as 95-100°F. For this reason, ales are typically brewed in these ranges to quickly bring it through the fermentation cycle due to the increased chemical activity at the higher temperatures. However, short of filtering, this fast fermentation process provides a somewhat cloudier, hardier beer that some may find distasteful. But lager’s cold-hardiness allows it to remain active at much lower temperatures. In Germany, Bavaria and other areas of central Europe, winter temperatures allowed this type of yeast to gain favor among brewers, especially following the decree of Bavaria’s Duke Albrecht V in 1553 that no brewing was to take place over the summer. At the same time, the lower temperature provides slower fermentation by half, slowing down the process and allowing for a for a clearer brew. Cold Storage Lagers also go through an additional step that ales do not, one of cold conditioning to develop further clarity. Indeed, the variety is named for the German word lagern, which means storage. Traditionally brewed in caves throughout central Europe, the cold temperatures meant the beer would be kept for a longer period of time at a cool temperature as compared to ale’s warmer storage in other parts of the world. This would have a strong effect on the finished product, providing a better clarity and finer flavor in lagers than may be found in ales of the same time period. Though it is believed that this particular property was discovered accidentally, when lager stored in brewing caves was left longer than intended, it is now a virtually indispensable step in brewing lagers, consisting of a period of cold conditioning from four to ten weeks in length. This step allowed more of the yeast, proteins and hops to settle out of the lager, improving clarity dramatically and reducing chill haze, which forms when an ale which has not undergone the cold treatment phase is cooled for the first time and the additional solids in the ale begin to cause the haze effect. Hops Content Though hops are present in almost every beer style, they tend to be in different quantities in an ale compared to a lager. In a lager’s cold treatment process, the finer flavors of the hops are able to come out, providing a more delicate flavor without sacrificing the additions the hops can make to the finished beer. By comparison, hops tend to be found in much higher content in ales, especially as the hops provide a protective element to the beer as it is being fermented at higher temperatures. However, the faster, warmer process of brewing ale also means that there may be more bitterness within in the finished beer, which can be a detriment or a positive factor, depending on your own personal taste and the style in which is being brewed. Which Ingredients? For the most part, all beers include a particular range of ingredients: water, grain, yeast and hops. However, a beer purity law passed in Germany in 1516, commonly referred to as Reinheitsgebot, limited the ingredients to only malted grain, water and hops. Though yeast was undoubtedly part of the process, it was several centuries before science sorted out the particular organism responsible for the fermentation process. Because of the popularity of lagers in the region, as well as the above-mentioned ban on summer brewing, lagers have traditionally remained bound to these ingredients, though brewers have always experimented to a certain extent. Though there have been some change in the grains used in American mega-breweries, most of the remaining ingredients largely remain the same, with the dawn of modern refrigeration techniques allowing these lagers to provide the same clear, crisp, smooth beers that has made such greats as Anheuser-Busch, Miller and Pabst into household names. Ales, on the other hand, have not developed under such constraints. This has allowed a wide range of various styles to be developed in different regions of the world, running the entire range from IPAs to stouts, with various sub-styles and experimental batches branching off from there. A number of other ingredients have also come to be added, including fruit flavorings and a wide range of grains, including wheat, to create hundreds of different styles only limited by the imagination of the brewer. Because of this wide range of options and constant innovation of breweries, craft beer has not only exploded in popularity, but the world of beer has been flooded with a near endless number of unique flavors and aromas. TL;DR: It’s All in the Details In general, there are many differences between ales and lagers. But, to keep it concise, here’s a quick summary. Ales tend to be darker, have a cloudier appearance, higher alcohol content and a stronger, fruitier, more robust flavor with stronger bitter tones from the hops due to the higher amount of hops, faster, more thorough fermentation. Lagers tend towards a lighter, clear appearance, have a lower alcohol content and a sweeter, smoother, crisp flavor from the higher sugar content, slower fermentation and cold treatment. These aspects are most strongly affected by the yeast and brewing practices, with the additional flavors and post-fermentation handling also playing an important role in the final product. Though the differences between ale and lager are many, having a better idea of what facets of the brewing process and ingredients affect the final product allow you to have a better appreciation for the differences between the two varieties. These differences are not set in stone, with some lager yeasts surviving up into the 60-65°F range and some ales going through a cold conditioning stage, producing brews that transcend the differences between these two varieties. Though lagers have enjoyed a significant market share, the strong growth trend of ales in microbreweries and import beers provide an excellent alternative to those who prefer a beer with a bit more substance.