The basic ingredients of beer are water; a fermentable starch source, such as malted barley; and yeast. It is common for a flavouring to be added, the most popular being hops. A mixture of starch sources may be used, with the secondary starch source, such as corn, rice and sugar, often being termed an adjunct, especially when used as a lower cost substitute for malted barley.Water
Beer is composed mostly of water, and water used to make beer nearly always comes from a local source. The mineral components of water are important to beer because minerals in the water influence the character of beer made from it. Different regions have water with different mineral components. As a result, different regions are better suited to making certain types of beer. For example, Dublin has hard water well-suited to making stout, such as Guinness, and Pilzen has soft water well-suited to making pale lager, such as Pilsner Urquell. As a result, it is argued that the mineral components of water have an influence on the character of regional beers.
Starch source
The starch source in a beer provides the fermentable material in a beer and is a key determinant of the character of the beer. The most common starch source used in beer is malted grain. Grain is malted by soaking it in water, allowing it to begin germination, and then drying the partially germinated grain in a kiln. Malting grain produces enzymes that convert starches in the grain into fermentable sugars. Different roasting times and temperatures are used to produce different colours of malt from the same grain. Darker malts will produce darker beers.
Nearly all beer includes barley malt as the majority of the starch. This is because of its fibrous husk, which is important in the sparging stage of brewing, and high concentration of amylase, a digestive enzyme which facilitates conversion of starch into sugars. Other malted and unmalted grains (including wheat, rice, oats, and rye, and less frequently, corn and sorghum) may be used.
Hops
Crushed hops
The flower of the hop vine is used as a flavouring and preservative agent in nearly all beer made today. The flowers themselves are often called "hops." The use of hops in beer was recorded by captive Jews in Babylon around 400 BCE. Hops were used by monastery breweries, such as Corvey in Westphalia, Germany, from 822 CE,, though the date normally given for widespread cultivation of hops for use in beer is the thirteenth century.
Hops contain several characteristics that brewers desire in beer: hops contribute a bitterness that balances the sweetness of the malt; hops also contribute floral, citrus, and herbal aromas and flavours to beer; hops have an antibiotic effect that favours the activity of brewer's yeast over less desirable microorganisms; and the use of hops aids in "head retention", the length of time that a foamy head created by carbonation will last. The bitterness of beers is measured on the International Bitterness Units scale. Beer is the sole major commercial use of hops.
In the past, other plants have been used for similar purposes; for instance, Glechoma hederacea. Combinations of various aromatic herbs, berries, and even ingredients like wormwood would be combined into a mixture known as gruit and used as hops are now used.
Yeast
Main articles: Brewer's yeast, Saccharomyces cerevisiae, and Saccharomyces uvarum
Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolizes the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. In addition to fermenting the beer, yeast influences the character and flavour. The dominant types of yeast used to make beer are ale yeast (Saccharomyces cerevisiae) and lager yeast (Saccharomyces uvarum); their use distinguishes ale and lager. Brettanomyces ferments lambics, and Torulaspora delbrueckii ferments Bavarian weissbier. Before the role of yeast in fermentation was understood, fermentation involved wild or airborne yeasts. A few styles such as lambics rely on this method today, but most modern fermentation adds pure yeast cultures directly to wort.
Clarifying agent
Some brewers add one or more clarifying agents to beer. Common examples of these include isinglass finings, obtained from swimbladders of fish; kappa carrageenan, derived from seaweed; Irish moss, a type of red algae; polyclar (artificial), and gelatin. Clarifying agents typically precipitate out of the beer along with protein solids, and are found only in trace amounts in the finished product.
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Types and styles of beer
A great many beers are brewed across the globe. Local traditions will give beers different names, giving the impression of a multitude of different styles. However, the basics of brewing beer are shared across national and cultural boundaries.
The British beer writer Michael Jackson wrote about beers from around the world in his 1977 book The World Guide To Beer and organised them into local style groups based on local information. This book had an influence on homebrewers in United States who developed an intricate system of categorising beers which is exemplified by the Beer Judge Certification Program.
The traditional European brewing regions — Germany, Belgium, the United Kingdom, Ireland, Poland, the Czech Republic, Denmark, The Netherlands and Austria — have local varieties of beer. In some countries, notably the USA, Canada and Australia, brewers have adapted European styles to such an extent that they have effectively created their own indigenous types.
Categorising by yeast
A common method of categorizing beer is by the behaviour of the yeast used in the fermentation process. In this method of categorizing, those beers which use a fast-acting yeast, which leaves behind residual sugars, are termed ales, while those beers which use a slower and longer acting yeast, which removes most of the sugars, leaving a clean and dry beer, are termed lagers.
Differences between some ales and lagers can be difficult to categorise. Steam beer, Kölsch, Alt, and some modern British Golden Summer Beers use elements of both lager and ale production. Baltic Porter and Bière de Garde may be produced by either lager or ale methods or a combination of both. However, lager production results in a cleaner tasting, dryer and lighter beer than ale.
Cask ales
A modern ale is commonly defined by the strain of yeast used and the fermenting temperature.
Ales are normally brewed with top-fermenting yeasts (most commonly Saccharomyces cerevisiae) , though a number of British brewers, including Fullers and Weltons, use ale yeast strains that have less pronounced top-fermentation characteristics. The important distinction for ales is that they are fermented at higher temperatures and thus ferment more quickly than lagers.
Ale is typically fermented at temperatures between 15 and 24 °C (60 and 75 °F). At these temperatures, yeast produces significant amounts of esters and other secondary flavour and aroma products, and the result is often a beer with slightly "fruity" compounds resembling apple, pear, pineapple, banana, plum, or prune, among others. Typical ales have a sweeter, fuller body than lagers.
Lager
Lager is the English name for bottom-fermenting beers of Central European origin. They are the most commonly consumed beers in the world. The name comes from the German lagern ("to store"). Lagers originated from European brewers storing beer in cool cellars and caves and noticing that the beers continued to ferment, and also to clear of sediment. Lager yeast is a bottom-fermenting yeast (e.g., Saccharomyces pastorianus), and typically undergoes primary fermentation at 7–12 °C (45–55 °F) (the "fermentation phase"), and then is given a long secondary fermentation at 0–4 °C (32–40 °F) (the "lagering phase"). During the secondary stage, the lager clears and mellows. The cooler conditions also inhibit the natural production of esters and other byproducts, resulting in a "crisper" tasting beer.
Modern methods of producing lager were pioneered by Gabriel Sedlmayr the Younger, who perfected dark brown lagers at the Spaten Brewery in Bavaria, and Anton Dreher, who began brewing a lager, probably of amber-red colour, in Vienna in 1840–1841. With improved modern yeast strains, most lager breweries use only short periods of cold storage, typically 1–3 weeks.
Lambic beers: spontaneous fermentation
Lambic beers, a speciality of Belgian beers, use wild yeasts, rather than cultivated ones. Many of these are not strains of brewer's yeast (Saccharomyces cerevisiae), and may have significant differences in aroma and sourness. Yeast varieties such as Brettanomyces bruxellensis and Brettanomyces lambicus are quite common in lambics. In addition, other organisms such as Lactobacillus bacteria produce acids which contribute to the sourness.
Pale and dark beer
The most common colour is a pale amber produced from using pale malts. Pale lager is a term used for beers made from malt dried with coke. Coke had been first used for roasting malt in 1642, but it wasn't until around 1703 that the term pale ale was first used.
In terms of sales volume, most of today's beer is based on the pale lager brewed in 1842 in the town of Pilsen, in the Czech Republic. The modern pale lager is light in colour with a noticeable carbonation, and a typical alcohol by volume content of around 5%. The Pilsner Urquell, Bitburger, and Heineken brands of beer are typical examples of pale lager, as are the American brands Budweiser, Coors, and Miller.
Dark beers are usually brewed from a pale malt or lager malt base with a small proportion of darker malt added to achieve the desired shade. Other colourants — such as caramel — are also widely used to darken beers. Very dark beers, such as stout use dark or patent malts that have been roasted longer. Guinness and similar beers include roasted unmalted barley.
A great many beers are brewed across the globe. Local traditions will give beers different names, giving the impression of a multitude of different styles. However, the basics of brewing beer are shared across national and cultural boundaries.
The British beer writer Michael Jackson wrote about beers from around the world in his 1977 book The World Guide To Beer and organised them into local style groups based on local information. This book had an influence on homebrewers in United States who developed an intricate system of categorising beers which is exemplified by the Beer Judge Certification Program.
The traditional European brewing regions — Germany, Belgium, the United Kingdom, Ireland, Poland, the Czech Republic, Denmark, The Netherlands and Austria — have local varieties of beer. In some countries, notably the USA, Canada and Australia, brewers have adapted European styles to such an extent that they have effectively created their own indigenous types.
Categorising by yeast
A common method of categorizing beer is by the behaviour of the yeast used in the fermentation process. In this method of categorizing, those beers which use a fast-acting yeast, which leaves behind residual sugars, are termed ales, while those beers which use a slower and longer acting yeast, which removes most of the sugars, leaving a clean and dry beer, are termed lagers.
Differences between some ales and lagers can be difficult to categorise. Steam beer, Kölsch, Alt, and some modern British Golden Summer Beers use elements of both lager and ale production. Baltic Porter and Bière de Garde may be produced by either lager or ale methods or a combination of both. However, lager production results in a cleaner tasting, dryer and lighter beer than ale.
Cask ales
A modern ale is commonly defined by the strain of yeast used and the fermenting temperature.
Ales are normally brewed with top-fermenting yeasts (most commonly Saccharomyces cerevisiae) , though a number of British brewers, including Fullers and Weltons, use ale yeast strains that have less pronounced top-fermentation characteristics. The important distinction for ales is that they are fermented at higher temperatures and thus ferment more quickly than lagers.
Ale is typically fermented at temperatures between 15 and 24 °C (60 and 75 °F). At these temperatures, yeast produces significant amounts of esters and other secondary flavour and aroma products, and the result is often a beer with slightly "fruity" compounds resembling apple, pear, pineapple, banana, plum, or prune, among others. Typical ales have a sweeter, fuller body than lagers.
Lager
Lager is the English name for bottom-fermenting beers of Central European origin. They are the most commonly consumed beers in the world. The name comes from the German lagern ("to store"). Lagers originated from European brewers storing beer in cool cellars and caves and noticing that the beers continued to ferment, and also to clear of sediment. Lager yeast is a bottom-fermenting yeast (e.g., Saccharomyces pastorianus), and typically undergoes primary fermentation at 7–12 °C (45–55 °F) (the "fermentation phase"), and then is given a long secondary fermentation at 0–4 °C (32–40 °F) (the "lagering phase"). During the secondary stage, the lager clears and mellows. The cooler conditions also inhibit the natural production of esters and other byproducts, resulting in a "crisper" tasting beer.
Modern methods of producing lager were pioneered by Gabriel Sedlmayr the Younger, who perfected dark brown lagers at the Spaten Brewery in Bavaria, and Anton Dreher, who began brewing a lager, probably of amber-red colour, in Vienna in 1840–1841. With improved modern yeast strains, most lager breweries use only short periods of cold storage, typically 1–3 weeks.
Lambic beers: spontaneous fermentation
Lambic beers, a speciality of Belgian beers, use wild yeasts, rather than cultivated ones. Many of these are not strains of brewer's yeast (Saccharomyces cerevisiae), and may have significant differences in aroma and sourness. Yeast varieties such as Brettanomyces bruxellensis and Brettanomyces lambicus are quite common in lambics. In addition, other organisms such as Lactobacillus bacteria produce acids which contribute to the sourness.
Pale and dark beer
The most common colour is a pale amber produced from using pale malts. Pale lager is a term used for beers made from malt dried with coke. Coke had been first used for roasting malt in 1642, but it wasn't until around 1703 that the term pale ale was first used.
In terms of sales volume, most of today's beer is based on the pale lager brewed in 1842 in the town of Pilsen, in the Czech Republic. The modern pale lager is light in colour with a noticeable carbonation, and a typical alcohol by volume content of around 5%. The Pilsner Urquell, Bitburger, and Heineken brands of beer are typical examples of pale lager, as are the American brands Budweiser, Coors, and Miller.
Dark beers are usually brewed from a pale malt or lager malt base with a small proportion of darker malt added to achieve the desired shade. Other colourants — such as caramel — are also widely used to darken beers. Very dark beers, such as stout use dark or patent malts that have been roasted longer. Guinness and similar beers include roasted unmalted barley.
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