This primer will tell you mostly everything you need to know about how to interpret those acronyms and numbers on the wall/menu of the beer hall of your choosing. The most common are #3 and #4, but an understanding of all 5 will really give you an appreciation for what you’re ordering and will impress your friends.
#1: Original Gravity (OG): This reveals the specific gravity (density/sugar content) of the wort before fermentation begins. Essentially, it is potential for alcohol – alcohol is just fermented sugars right? By itself, it is not a very helpful stat, but it is relatively popular nonetheless. It’s usually expressed in the conventional format, 1.055 for example, or in degrees Plato (14°). The conversion between the two is easy, Plato * 4 roughly equals the last 2 digits on the conventional gravity. 20° Plato is the same as 1.080. This value can range widely, 1.045-1.110 are typical values.
#2 Final Gravity (FG): Another gravity measurement, this time at the end of fermentation. This tells you how many residual sugars are left in the brew when the yeast is done with its work. This number can help you determine how malty a beer will taste and how balanced it will be with the hops included. Example: A beer shows an FG of 1.012 and 80 IBUs (we’ll get to that soon). Pretty good chance that is an IPA that is all about the hop showcase, not trying to balance the malty sweetness as much…on the other end of the spectrum you may have an FG of 1.022 and 30 IBUs – that could be an English Old Ale, meant to be sweeter with the malts as the focus. Typical ranges are 1.010-1.024.
#3: Alcohol by Volume (ABV): Doesn’t need much explanation in terms of what it is (and how it makes you feel), but do you know how it’s calculated/measured? You cannot (as far as I’m aware) measure the alcohol content in beer, you have to measure the Original Gravity and the Final Gravity and do this: (OG – FG)*131 = ABV. Example, Double IPA: (1.085-1.016) *131 = 9% ABV. Nerd out.
#4: International Bitterness Units (IBUs): I won’t go into how this is calculated (you’re welcome), but this value tells you the bitterness given to the beer by the hops used in the brewing process. Just about all types of beer use hops in the boil, and therefore have some bitterness. Brewing is all about balance, and the dance between the hops and malts used. Don’t assume that a beer with 50 IBUs will be more bitter (tasting) than one with 35. The former could be a big stout, with loads of heavy and complex malt used which require the bitterness to balance it out, otherwise it would taste syrupy and over-sweet. The latter could be a german pilsner, with less/simpler malt used, letting the hops shine. So there is not, or should not be a threshold here that you stay away from based on limited experience. You’ll have an overly hopped pale at 65IBUs that is too bitter, and a Black IPA with the same 65IBUs could be juuuuuuust right. Typical ranges are from 15-100IBU. You can’t taste the difference after 100.
#5 SRM: This is a less common measurement, unless you are a brewer or go to brewery website to look at the stats of certain beers (everyone does that right?). SRM is ‘Standard Reference Measurement’ used by brewers to describe the color of the beer. Depending on the malts used, brewers tweak this value to produce the look of the beer desired. Basically, the scale goes from 2-40 from light to dark, although it does not have anything to do with clarity of the beer. The photo below shows the 3 beers I have on tap now at my house – Pilsner (3.5), Fresh Hop Amber (13.8) and Black IPA (38).
Hope you enjoyed the info, it will make you appreciate the beer in your hand more – I promise. Now drink up – cheers!