ABV, IBU, SRM and gravity: the numbers on a beer label
What the numbers on a beer mean: ABV for strength, IBU for bitterness, SRM and EBC for colour, and original and final gravity, with the BJCP strength bands.
Every style page on BeerCorp opens with a few numbers. They come from the BJCP style guidelines, and together they tell you how strong, how bitter and how dark a beer is before you open it.
ABV: strength
Alcohol by volume is the share of the beer that is alcohol. A 500 ml glass of 5% beer holds 25 ml of it. The BJCP sorts styles into four bands:
| Band | ABV | Examples |
|---|---|---|
| Session | under 4% | Berliner Weisse, many bitters |
| Standard | 4–6% | Czech Pilsner, Irish Dry Stout |
| High | 6–9% | Belgian Dubbel, American IPA at the top of its range |
| Very high | over 9% | Imperial Stout, English Barleywine |
Some labels give alcohol by weight instead, which reads lower for the same beer.
IBU: bitterness
International Bitterness Units measure the bitter compounds from hops, in a laboratory. A Gueuze sits near 0, a German Pils at 22–40, an Imperial Stout at up to 90. The number does not tell the whole story: malt sweetness hides bitterness, so a rich barleywine at 60 IBU can taste less bitter than a dry pils at 40.
SRM and EBC: colour
The American SRM scale runs from about 2 for pale straw to 40 and beyond for black; the European EBC scale gives roughly twice the number for the same beer. The BJCP groups colours into pale (straw to gold), amber (amber to copper-brown) and dark (dark brown to black). BeerCorp uses five bands, from pale to black.
Original and final gravity
Gravity measures how dense the liquid is compared with water, which sits at 1.000. Original gravity (OG), taken before fermentation, shows how much sugar the yeast has to eat: 1.044 for a light lager, 1.100 and more for a strong ale. Final gravity (FG), taken after, shows how much is left. The gap between them gives the alcohol; a low FG means a dry beer, a high one a sweeter, fuller beer. Czech brewers give the same measure in degrees Plato, so a 12° lager started at about 12% sugar by weight.
Sources
Checked .
- Introduction to Beer Styles — Beer Judge Certification Program
- Beer Glossary — CraftBeer.com, Brewers Association