Ales and Lagers
Ales and lagers are the two main beer styles. Most all sub styles of beer are differentiated into sub styles of ales and lagers. Ales and lagers differ in 6 major ways:
One of the brewer’s many choices during the brewing process is the selection of a yeast strain. The mixture of hot water and malt sugars created in the brewing process, called wort, is hearty a meal for the tiny fungus called saccharomyces. The yeast converts this meal into two by-products essential for our enjoyment of beer; alcohol and carbon dioxide. Ale yeast, known as saccharomyces cervisiae, prefers a warmer fermentation temperature and works quickly; on the other hand, lager yeast, saccharomyces uvarum, works more slowly and at cooler temperatures. Ale fermentation can be completed in as little as a week, and can impart earthy, fruity aromas prized in many beer styles. Lager yeast metabolize sulfites during their longer, cooler fermentation process which tends to give a “rotten eggs” smell to the fermenting beer. The longer fermentation and lagering thereafter eliminate this odor and produce a brew with a clean, crisp flavor profile.
- Top fermenting yeasts, saccharomyces cervisiae, form a foam at the top of the wort during fermentation
- Fermented and conditioned at warm temperatures between 65° -73° F
- Yeast used in ales usually has a fruity aroma
- Many ale strains have a high alcohol tolerance and will produce strong beers
- After fermentation, usually conditioned for no more than a few weeks
- Bottom fermenting yeast , saccharomyces uvarum
- Longer fermentation time
- Fermented and conditioned at cool temperatures 35° - 55° F
- Very slight dimethylsulfide (DMS) aroma is acceptable in the finished beer
- Aged for a few months after fermentation
The basic ingredients of beer are water, a source of starch, yeast and a source of flavoring. Malted barley, usually the starch content in beer, is both the main source of strength and the key flavoring agent. The malted grain produces enzymes that convert starches into fermentable sugars. Yeast metabolizes the sugars taken for the grain, which produces alcohol and carbon dioxide. It also impacts the beer’s character and flavor. Last but not least, hops kick up the flavor and function as a preservative in nearly all beers. Ales and lagers are both made with the same four ingredients. Only the brewing process yields beers that are so different. And delicious.
- Top fermenting yeast
- Bottom fermenting yeast
Ale yeasts tend to have characteristic flavors and aromas that enhance the finished beer. Aside from the yeast and specialty malts, fruits are the most common and popular additives to flavor beer. Hops are used not only for their preservative qualities, but for their aromas and flavors which range from simple bitterness to subtle notes of pine and tropical fruit. Brewers have used real fruit for centuries as well. Cherry, raspberry, peach and black currant are a few of the most popular fruit flavors. Sugars like lactose (milk sugar), honey, candy sugar, molasses, and maple syrup are used, too. Spices are not uncommon in beer. Coriander, juniper berries, nutmeg, cinnamon and ginger are often used.
- More complex flavor
- Yeast adds to the flavor profile
- Tend toward flavor extremes – bitter, fruity, sweet
- Most bitter, hoppy styles are ales
- Smoother, crisper, and more subtle in taste (and aroma)
- Malts and hops are the keys to lager flavor
- Yeast adds little or nothing to the flavor profile
- Clean to slightly acidic taste and aroma in lighter lagers
The mouthfeel, or “body” of the beer is the sensation in the mouth of fullness in the beer. Different levels of proteins, dextrins (unfermented sugars), and carbonation in the beer provide for the varying levels of perceived fullness or thickness in beer. Beer ‘body’ is usually classified as light, medium or full. Full-bodied beers tend to have a higher sugar content than lighter ones.
Carbonation is another big variable effecting mouthfeel. Beers ‘carbonated’ with nitrogen rather than carbon dioxide have a thick and creamy mouthfeel and sport a head with tiny bubbles. Highly carbonated beers, such as many Belgian ales and American lagers, give a prickly sensation in the mouth and tend to finish dry. Beers with higher alcohol contents tend to have a lower carbonation level, thicker mouthfeel, and lingering finish.
- Higher amount of residual sugars
- Tend to be heavier in mouthfeel, but depends upon style
- Lower amount of residual sugars
- Tend to be lighter in mouthfeel but depends upon style
Beer color gets pretty scientific. We use what we call the Standard Reference Method, or SRM. It’s a measurement of the loss of light in a wavelength passing through 1 cm of beer. The light loss represents absorption, which is scaled to a constant. The SRM number given represents one point in the absorption spectrum of beer. It’s the blend of malted grains that brings beer in different colors. The exposure of the grains to the kiln process is the final determinant. Both ales and lagers run the range of the light-to-dark spectrum. Both can go from a very light yellow-greenish, straw-like color to dark chocolate browns, and even shades of pinks and reds in fruit beers.
- Deep golden to amber
- Usually translucent
- Light or yellow golden
- Almost transparent
Clarity is an aspect of beer that depends on the style of the beer being brewed. Malting, conditioning, filtration, packaging and storage play roles here. Unless a beer has haziness as a hallmark, all beer should be poured and served clear. Haze can have a number of causes, including proteins precipitating in the beer when chilled. You see this in unfiltered craft beers a lot. It’s harmless; it’s flavorless and completely disappears as the beer warms up. Yeast can cause haze and sometimes it’s done deliberately. Old or mishandled beer can be heavily hazy and even have “snowflakes” in the liquid which are proteins that have precipitated out of the beer. Wheat beer lovers welcome the haziness. That said, most all barley-malt-only beers are designed to be crystal clear.
Some brewers add clarifying agents to their beers, which typically precipitate out of them. Typical clarifying agents are isinglass (obtained from swim bladders of fish), Irish moss (basically, seaweed), polyclar (artificial), and gelatin.
- Many ale styles are intentionally cloudy
- Lagers regardless of color should be clear.