Brewers language, a mythical way of communicate that goes back to the days of yesteryear and somewhat beyond…..
No seriously. There many words in the brewers language that is self explanatory, but with a mix of german, english, probably some french and greek and so on and so on, there will be some words that you only know the sound of, but not the meaning of.
The great John J Palmer from Midland, Michigan, author of How to brew, has explained many of these, if not all of them, but still, I will mention some of the most used terms here.
Best I can think of is to start out with is GRAVITY. This one has been used and misused and misunderstood by many. But it is really quite simple. You measure the gravity of the liquid that you work with. Simple as that. But what about SG and OG and FG you say? Well, it reads, Specific Gravity, Pre-boil Gravity, Original Gravity and Final Gravity. All in all it is Gravity, just measured at different stages. Specific Gravity is the gravity that you take at any specific point. So Pre-boil Gravity is the Specific Gravity of the wort after sparge and before boil. Really says it right there in the word. Original Gravity is the Specific Gravity of the wort after boil before fermentation. That leaves us then with Final Gravity. This is the specific Gravity of the wort after fermentation. Though calling it wort would really be wrong at this stage as the yeast would, on Final Gravity, have transformed the wort you brew, to beer.
To summarize Gravity:
Specific Gravity (SG): Gravity measured at any given point.
Pre-Boil Gravity(PBG): Gravity after sparge, before boil.
Original Gravity (OG): Gravity after boil before fermentation.
Final Gravity (FG): Gravity after fermentation.
These measurements are important if you want to have a bit of control on your brewing process. It will tell you how your mash process is doing. Did you extract enough fermentable sugars and flavour components after sparging? What is the gravity after my boil? Should I boil some extra to get higher GRAVITY? Lots of things. And also it will tell you how much ABV, alcohol by volume or just plain alcohol, you have in your finished bottled or kegged beer.
To calculate ABV there is quick way of doing this. Simply extract FG from OG and multiply by 0.132.
(OG-FG) x 0,132 =ABV
(1.050 – 1.010) x 0,132=5,28%
As you can see, there is many things to remember, but do not let this put you off. It will stick to the back of your brain quickly once you have used it a couple times.
On the next page, I will go more into the different ways you can measure SG.