Measurement of Beer
Beer is measured and assessed by bitterness, by strength and by colour. The perceived bitterness is measured by the International Bitterness Units scale (IBU), defined in co-operation between the American Society of Brewing Chemists and the European Brewery Convention. The international scale was a development of the European Bitterness Units scale, often abbreviated as EBU, and the bitterness values should be identical.
Colour
Paulaner dunkel - a dark lagerBeer colour is determined by the malt. The most common colour is a pale amber produced from using pale malts. Pale lager and pale ale are terms used for beers made from malt dried with coke. Coke was first used for roasting malt in 1642, but it was not until around 1703 that the term pale ale was 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 present-day Czech Republic. The modern pale lager is light in colour with a noticeable carbonation (fizzy bubbles) 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. Some have roasted unmalted barley.
Strength See also: Beer measurement#By strength Beer ranges from less than 3% alcohol by volume (abv) to around 14% abv, though this strength can be increased to around 20% by re-pitching with champagne yeast, and to 55% abv by the freeze-distilling process. The alcohol content of beer varies by local practice or beer style. The pale lagers that most consumers are familiar with fall in the range of 4–6%, with a typical abv of 5%. The customary strength of British ales is quite low, with many session beers being around 4% abv. Some beers, such as table beer are of such low alcohol content (1%–4%) that they are served instead of soft drinks in some schools.
The alcohol in beer comes primarily from the metabolism of sugars that are produced during fermentation. The quantity of fermentable sugars in the wort and the variety of yeast used to ferment the wort are the primary factors that determine the amount of alcohol in the final beer. Additional fermentable sugars are sometimes added to increase alcohol content, and enzymes are often added to the wort for certain styles of beer (primarily "light" beers) to convert more complex carbohydrates (starches) to fermentable sugars. Alcohol is a by-product of yeast metabolism and is toxic to the yeast; typical brewing yeast cannot survive at alcohol concentrations above 12% by volume. Low temperatures and too little fermentation time decreases the effectiveness of yeasts and consequently decreases the alcohol content.
Exceptionally strong beers The strength of beers has climbed during the later years of the 20th century. Vetter 33, a 10.5% abv (33 degrees Plato, hence Vetter "33") doppelbock, was listed in the 1994 Guinness Book of World Records as the strongest beer at that time, though Samichlaus, by the Swiss brewer Hürlimann, had also been listed by the Guinness Book of World Records as the strongest at 14% abv. Since then, some brewers have used champagne yeasts to increase the alcohol content of their beers. Samuel Adams reached 20% abv with Millennium,[99] and then surpassed that amount to 25.6% abv with Utopias. The strongest beer brewed in Britain was Baz's Super Brew by Parish Brewery, a 23% abv beer.
The product that is claimed to be the strongest beer made is The End of History, a 55% Belgian ale, made by the Scottish brewery BrewDog in 2010, who also made Sink The Bismarck!, a 41% abv IPA, and Tactical Nuclear Penguin, a 32% abv Imperial Stout; these are made using the eisbock method of freeze distilling in which the brewery freeze distils a strong ale, gradually removing the ice and freezing again until the beer reaches the strength required, a process that may class the finished products as spirits rather than beer.The German brewery Schorschbräu's Schorschbock—a 31% abv eisbock, and Hair of the Dog's Dave—a 29% abv barley wine made in 1994, both used the same freeze distilling method. A 60% abv blend of beer with whiskey was jokily claimed as the strongest beer by a Dutch brewery in July 2010.
