The Robust Porter is ready to bottle. I checked the gravity of the beer one more time to be sure that fermentation is completely finished, and it showed exactly the same number as last week, 1.019.
'brew-along' on Serious Eats
Today, take a sample using a sanitized auto-syphon racking cane to check your beer's gravity and give it a taste. Using that final gravity number, you'll be able to determine the approximate alcohol content of your beer.
Fermentation looks like it's finishing up and the airlock bubbles have slowed to almost nothing. As the yeast complete their job of processing the sugar, they clump together and settle to the bottom. Even though they're not really producing alcohol anymore, they are working to improve the flavor of the beer.
On Day 4, there's still a thick krausen on the top of my Robust Porter, the airlock is bubbling away and the yeast are still chomping away on the sugar. I stick a fermometer (a fermentor-thermometer) to the side of each of my carboys and fermenting buckets. These allow me to keep an eye on the temperature of beer during fermentation.
Fermentation is in full force now! The yeast have occupied every milliliter of the wort and they're breaking down sugar at a rapid rate. That thick, ugly foam that is on the top is called Krausen (a word derived from German, pronounced "KROY-zen").
Here we are, the day after pitching the yeast into the wort for our Robust Porter. It may look like nothing is going on here, but that is far from true. In order to understand what's really going on in this picture, we're going to have to get into a bit of science, so hold on to your beer-geek hat.
Robust Porter is what I like to call an "Americanized" version of the classic English Brown Porter style: the flavors are bolder, the alcohol content is a little higher and the hop character is more assertive. Today we'll brew it, and then we'll check up on it each day this week so you can get and idea of what you should expect when you brew it on your own.