Bottling! About 3/4 cup of corn sugar is mixed with water, boiled for a few minutes, then cooled to room temperature. It is then combined with the fermented beer in a large food-grade plastic bucket, and dispensed into the bottles, one at a time. Everything at this stage needs to be kept *very* clean, or else airborne yeast and bacteria can get in and ruin the whole thing.
The small amount of sugar solution provides a sort of “last meal” for the yeast, which have been dormant for a few days now. They go “Holy crap, food!” and gobble it up, creating a small extra bit of alcohol, but more importantly, more CO2. This carbonates the beer, which makes it fizzy, and contributes to the frothy head (lol) when it’s poured out. Too little sugar, and it comes out flat… too much, and too much CO2 gets produced, and the bottles explode.
At this point, the beer more or less tastes the way it’s going to finally taste (and it’s pretty frigging good), minus the carbonation and plus a few floaty particles that will eventually settle to the bottom. In 1-2 weeks, it’ll be ready to go into the fridge for a few more days, and then be served. Huzzah!