Our beer descriptions include some technical terms that beer snobs everywhere want to know. Here are a few definitions to help the rest of you out.
OG: Original Gravity
This is the density of the beer the day it is brewed. The OG allows us to predict the potential alcohol production in the beer. (Higher OG means more sugar, which means more alcohol at the end of fermentation.) The units are in specific gravity, which is a unitless number comparing the density of the beer to that of water, which has a density of 1.0 grams/milliliter. A beer with an OG of 1060 has a density of 1.06 grams/milliliter.
ABV: Alcohol by Volume
Everyone's favorite number! We calculate the percentage of alcohol by comparing the OG (see above) with the TG (terminal or final gravity.) The difference in density tells us how much sugar the yeast consumed, thus telling us how much alcohol the little buggers produced. A pint of five percent beer contains approximately eight- tenths of an ounce of pure ethanol.
IBU: International Bitterness Unit
The measure of a beer's bitterness. The bitterness in beer comes from hops, specifically from a chemical called alpha acid. These acids dissolve in beer at a predictable rate. We use yet more math to determine how much gets into our beer during the boil. One milligram of alpha acid per liter of beer (also expressed as parts per million alpha acid) equals one IBU. Domestic lagers may have as few as three IBUs, while Imperial IPAs may have upwards of 100. Sensory science seems to indicate that increasing bitterness above 100 IBU does not correlate to a perceived increase in bitter flavor—that is, 100 IBU is about the limit of our taste buds. On a side note, women generally are able to detect bitterness at much lower thresholds than men. Researchers point to pregnancy as a possible explanation: bitter compounds are often toxic, and it was important for women to be able to detect these compounds to avoid harming their fetus.
OG: Original Gravity
This is the density of the beer the day it is brewed. The OG allows us to predict the potential alcohol production in the beer. (Higher OG means more sugar, which means more alcohol at the end of fermentation.) The units are in specific gravity, which is a unitless number comparing the density of the beer to that of water, which has a density of 1.0 grams/milliliter. A beer with an OG of 1060 has a density of 1.06 grams/milliliter.
ABV: Alcohol by Volume
Everyone's favorite number! We calculate the percentage of alcohol by comparing the OG (see above) with the TG (terminal or final gravity.) The difference in density tells us how much sugar the yeast consumed, thus telling us how much alcohol the little buggers produced. A pint of five percent beer contains approximately eight- tenths of an ounce of pure ethanol.
IBU: International Bitterness Unit
The measure of a beer's bitterness. The bitterness in beer comes from hops, specifically from a chemical called alpha acid. These acids dissolve in beer at a predictable rate. We use yet more math to determine how much gets into our beer during the boil. One milligram of alpha acid per liter of beer (also expressed as parts per million alpha acid) equals one IBU. Domestic lagers may have as few as three IBUs, while Imperial IPAs may have upwards of 100. Sensory science seems to indicate that increasing bitterness above 100 IBU does not correlate to a perceived increase in bitter flavor—that is, 100 IBU is about the limit of our taste buds. On a side note, women generally are able to detect bitterness at much lower thresholds than men. Researchers point to pregnancy as a possible explanation: bitter compounds are often toxic, and it was important for women to be able to detect these compounds to avoid harming their fetus.
