Ales and Lagers...How Are They Different?
There seems to be a lot of confusion out there about what the difference between ales and lagers are. Both ales and lagers are made with the same ingredients: water, malted barley, hops and yeast. The main difference between the two types of beer is the type of yeast that they use to ferment the sugars from the malted barley, and the temperature that they are fermented at.
Ales, Lagers, and the Yeast That Divides Them
There are two types of yeast that brewers use to turn the sugars from the wort into alcohol, and make beer. The first of the two types is a bottom fermenting yeast that is used to brew lagers. These bottom feeding yeast prefer cooler conditions as they do their job of fermenting. The usual preferred temperature is between about 47 and 60 degrees Fahrenheit, though there can be variances in temperature depending on the strand of yeast used. The low temperature that lager yeast prefers means that the batch will take a little longer to ferment than a batch of ale would, and they are a little more difficult for the average home brewer to brew.
Lagers can be considered the "German" style of beer. The colder temperatures in Germany meant that they needed a type of yeast that could withstand the low temperatures. Lager yeast will often give a maltier flavor than ale yeast does. Also, lagers tend to not be as experimental with tastes as ales are. The German purity laws from the 1500s would not allow brewers to put anything other than barley, hops, yeast and water into their beers. So, it's sort of been a tradition to keep brewing in that manner.
The second type of yeast that brewers use is a top fermenting yeast that is used for ales. Ale yeast is a little easier to manage because it prefers to ferment at higher temperatures. From my experience, you can usually get the best results between 62 and 74 degrees Fahrenheit. With both top fermenting and bottom fermenting yeast, if they are subjected to too high of temperatures, then you will get some off flavors in your brew. Read my article Home Brew Taste Like Apple Cider to see some reasons that your beer may come out bad.
Ales are more of an "English" tradition, and they tend to be much more complex than lagers are. Ales are very hoppy and can be bitter. If you're not sure what "hoppy" is, I would describe it as plant-like or earthy. Hops can produce many types of flavors and aromas that mimic various types of fruit flavors. For example, it's not uncommon to smell citrus smells in good ales.
Color & Alcohol Content
In spite of what you may have heard and read a few times, color and alcohol level cannot really be a way to distinguish an ale from a lager. Both types of beer come in lighter and darker colors. Likewise, both styles have high and low alcohol levels. To determine if it's an ale or a lager, you either have to ask what type it is, or taste it to find out. After you experience more quality beers, and take time to notice the subtle flavors, you will get better at determining what style you are tasting.
For the record, a pilsner is a type of lager. Many people seem to be confused by this, but a pilsner uses bottom feeding yeast to ferment. So, by default it's a lager. The big 3 (Bud, Miller, Coors) tend to taste somewhat different from regular lagers because they use adjuncts (corn, rice) instead of barley, which gives them their subdued flavor. But, they are still lagers because they use bottom feeding yeast.Just remember, the differences between an ale and a lager is whether the yeast is top or bottom fermenting. Types such as stouts, IPAs, doppelbocksâ€¦etc are all just types of ales and lagers.
Ales Vs Lagers Conclusion
So, there you have it. You know what really makes a lager a lager, and an ale an ale. There are many strands of top and bottom fermenting yeast available that give different flavors. If you're interested in learning more about yeast, then Yeast: The Practical Guide to Beer Fermentation has some good information.
Now you can go and impress your friends with your newfound knowledge when you go and have a beer with them. You'll be the most popular person at the party if you lay a few facts about types of yeast out there.Trust me, I know from experience, dude.