We just kegged our latest batch of beer, a rye IPA recipe called “Denny’s Favorite.” It’s also one of mine…
Listening: “Matty Groves” by Fairport Convention
Anne and I have both become more interested in our brewing, and we broke out the hydrometer for this batch. This measures the specific gravity (density as compared to the density of water): you measure the specific gravity before and after fermenting, and the difference between original gravity (OG) and final gravity (FG) corresponds to the difference in density between the sugary pre-ferment wort, and the beer after the sugars have been converted to alcohol. Plug these into a formula to get the amount of alcohol in the beer: we got an OG of 1.040 when we brewed a few weeks ago, and today our FG was 1.006, so our new batch is about 6.5% alcohol by volume. It should be carbonated and ready to drink in about a week, but other than a taste test we’ll probably save it for Sarah’s birthday party.
Listening: “Cello Song” by Nick Drake
But that sent me on a voyage of Internet discovery, which led me to issues like calculated vs measured beer gravities — and how do you calculate the gravity? You do it by looking at the potential sugar supply of the malt in your recipe, adjusted for the efficiency of your brewing process, and the “attenuation,” or sugar-converting power of your yeast, and how do you do all those things?
Listening: “Galileo” by the Indigo Girls
Well, now I know how, but these all come more into play when you are trying to create a beer recipe; since we usually just follow recipes we don’t really need to know these things — measuredOG and FG are fine for our purposes, and that’s our one step deeper into the process.
We are now waiting for Emmi & Kyle, and Ben (with possibly Candace) to arrive for our Christmas visit — we’ll be having the chili I made the other day, and tonight is the CAT Christmas Lights night ride, which had been rained out on Saturday.
Listening: “Watershed” by Vienna Teng