International Bitterness Unit

The International Bitterness Units scale, or simply IBU scale, provides a measure of the bitterness of beer, which is provided by the hops used during brewing. An IBU is one part per million of isohumulone — the higher number, the greater the bitterness.The bittering effect is less noticeable in beers with a high quantity of malt, so a higher IBU is needed in heavier beers to balance the flavor. For example, an Imperial Stout may have an IBU of 50, but will taste less bitter than an English Bitter with an IBU of 30, because the latter beer uses much less malt than the former. The technical limit for IBU's is around 100, others have tried to surpass this number but there is no real gauge after 100 IBUs when it comes to taste threshold.
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International bitterness unit (symbole IBU) est une unité utilisée par les brasseurs pour mesurer l'amertume de leurs bières.
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International Bitterness Unit (simbolo IBU) è un'unità utilizzata dai fabbricanti di birra per misurare l'amarezza del loro prodotto.Un IBU corrisponde a una parte per milione (ppm) di isohumulone (acido Þ), il componente chimico che proviene dal luppolo ed è responsabile del gusto amaro.L'IBU si calcola secondo la formula seguente:
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