 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, 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. In September 2011, the Scottish brewery BrewDog produced Ghost Deer, which, at 28%, they claim to be the world's strongest beer produced by fermentation alone. COUNT 5
QSN1 How much alcohol is contained in the beer Vetter 33? ANS1 10.5% QSN2 What was the strongest beer in 1994 according to the Guinness Book of World Records? ANS2 Vetter 33 QSN3 What brewing company produced the beer Millennium? ANS3 Samuel Adams QSN4 What year did the brewing company BrewDog start producing a beer called Ghost Deer? ANS4 2011 QSN5 What do brewing companies sometimes use to give more alcohol content to their beer? ANS5 champagne yeasts