entirely safe and fun

The home stretch!

The wort is fermented nearly dry at this point. It smells like wheat beer, it tastes like wheat beer… I think it may be wheat beer! Between today and yesterday, only one additional point (that is, .001 water densities) of solutes fermented out. The bubble rate is down to 4/min, which is probably high in that there was a bubble right at the beginning of my measurement interval. I think that the sampling theorem would normally dictate a sample interval of longer than one minute, at this point, for reliable measurement.

The last two days have seen the bubble rate at 6 and 4/min, the gravity at 1.0135 and 1.0125, and the change in SG at .0025 and .001, respectively. That leaves the correlation coefficient between bubble and SG change at .955, which I’ll call a high-quality result. Going forward, I’ll be more willing to trust the airlock as an indicator of fermentation progress than I was before.

If the final gravity is indeed 1.012-1.0125, then I’ll be looking at a beer with around 4.6% alcohol by volume, minus probably negligible losses to higher organics via secondary metabolic pathways. It’s right on target for the yeast strain’s 75% attenuation, assuming that a point or two of the weight of the beer was coming from sources other than fermentable sugars. Science is fun!

Part 1 of this series is here; part 2 is here. Part 3 is here.