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Updated: 20 January 2007
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The Basics |
WHAT IS BEER?
Quite simply, beer is fermented, hop flavored, malt sugar tea. There are four basic building blocks needed to make beer: water, malted barley, and hops. Yeast, (often listed as a fourth ingredient, although not a part of the finished product) is used to ferment the hop flavored malt sugar tea into a effervescent liquid with an average of between three and seven percent ethyl alcohol by weight. (In some cases, such as a Barley Wine, the alcohol content can go to almost 11% by weight.) Both beer and ale are made from essentially the same four building blocks with the major variation being the type of yeast used to ferment the product.
The following is a brief description of the four important building blocks of beer.
1. Water:
Water comprises over 90% of beer. In the past, the mineral content of natural springs, or artesian wells, constituted a major flavor factor in the beers that were produced in a specific region. Examples of naturally occurring water supplies that have resulted in distinctive beer styles are found at: Burton-on-Trent in the United Kingdom, (Bass Ale) and Esopus in New York State.
Today, brew masters can chemically adjust any water to create the exact "style" of beer desired. The chemicals added to the water are most often mineral salts such as Gypsum or Epsom Salts.
These salts cause the hop oils to develop specific pronounced flavor characteristics that enhance their use as flavoring agents.
Although the phrase "pure water" has been used extensively in advertisements for beers and ales, every brewery carefully adjusts the water they use to meet their specific flavor profile.
2. Malted Barley:
Malt (from the Old English – mealt) is any cereal grain after germination and before fully sprouting. This is “malted” grain.
To those involved in the brewing and production of fermented malt beverages, “malt” is the germinated, dried and perhaps slightly roasted grain of barley (Hordeum vulgare).
3. Yeast:
Yeast is the organism that metabolizes the sugar (maltose) in the wort into ethyl alcohol and carbon dioxide (CO2). The fermentation process is done in two steps. The "primary" fermentation converts most of the maltose to ethyl alcohol and CO2. The "secondary" fermentation finishes metabolizing the remaining sugar into the CO2 necessary to give the beer effervescence.
In traditional beer making there is also a "priming" that restarts the last of the fermentation in the bottles or kegs. This priming assures that the beer has natural carbonation. In mass-produced commercial beers and ales the carbonation is injected into the beer when it is bottled or kegged.
There are two kinds of yeast used in fermenting brew: Ale Yeast: (Saccharomyces Cerevisiae) An aerobic yeast that needs contact with oxygen to ferment, so it forms a thick layer at the top of the wort. It also works best when the ambient temperature is between 60-65F. Its fermentation also produces Esters. These are flavors that give the impression of apples, pears and, sometimes plums.
Lager yeast: (Saccharomyces Carlsbergensis) An anaerobic yeast that ferments at the bottom of the wort and functions best at temperatures between 35-40F. It produces few esters and takes much longer than ale yeast to complete fermentation.
4. Hops:
Hops come in many different varieties. As you read in the chapter on beer styles, different brewers use different varieties of hops. The brewers of Burton-on-Trent prefer the flavors of Kent hops for bittering their ales, while the brewers of Pilsen, in the Czech Republic have the aromatic hops of Sazz to finish their lagers with. In the United States the brewers of the West Coast have long had a love affair with the Cascade hops of Oregon, while the brewers of the mega-brews have succeeded in blending hops until their flavors just nip at the senses. Each variety has a particular bitter flavor as well as aroma. These two characteristics are important to remember when tasting a beer. The flavor of a particular hop may not quite match the initial aromatic sensation you receive when you first sample the bouquet that rises from the rich head of a perfectly poured glass of beer.
This concert of the bitter flavor and floral aroma from the hops, when combined with the sweet and, sometimes astringent, flavors of the malts used in the beer are also influenced by the flavors created by the specific yeast used to ferment the beer.
The Following two photographs are of the A-B hop farms in Idaho.
Adjuncts:
Although malt and hops are the main contributors to the flavor of beer and ale, in some cases there are additional flavors. Depending on whether you are drinking a beer or an ale you will also detect flavors that are created by the yeast during fermentation. The ale yeast creates esters that smell like apples, bananas, pears, and oranges.
Lager yeast creates much fewer esters, predominately grassy or new mown hay or, in some cases citric aromas. These esters are the exception rather than the rule because lager yeast ferments the sugars much more thoroughly than ale yeasts. Lager yeast takes at least 32 days to complete fermentation, while ale yeast takes a week at most.
(c) Peter LaFrance
29 September 2006