Yes, you got through brew day and now you are ready for your beer to ferment. You’ve added the yeast, and now what? What things should a brewer be looking for?

Photo Courtesy of: Nick Patrek

To start, make sure you have a lid sealed on your fermenter, or a stopper in your carboy. Without the fermenter being sealed the CO2 can escape from around the lid, and not force the CO2 through the airlock. Without this seal you may not know that the beer is fermenting. With a sealed fermenter make sure you are also using an airlock. An airlock gets filled with water and fits in a grommet in the lid, or in the hole of the drilled stopper. The airlock allows the CO2 to escape during fermentation, but doesn’t allow air back in. You may also see this referred to as closed fermentation.

The reason we do closed fermentations today is because of bacteria. We don’t want bad things coming in contact with our beer as it ferments. By using a lid and airlock we are minimizing the opportunity for bacteria to come in contact with our brew. We also use closed fermentations to prevent oxidation. If air can’t come in contact with the beer then we shouldn’t have problems with oxidation.

Also, the proper fermentation temp for ales is around 68 degrees. Try to make sure your beer is fermenting in are area that is fairly consistent with this temperature. Don’t place it in a three season porch where it can be 70 degrees during the day and 40 degrees at night. Don’t place it directly on a basement floor as the fermenter will pick up the temperature of the floor, which can be around 50 degrees in some cases. Some people use towels under the fermenter to get it off the floor. I use an old wood create. A little cooler, or warmer, is fine, but don’t get too far away from the 68 degree zone.

With everything properly in place it will take the yeast between 8 hours to 72 hours to show visible signs of fermentation. The easiest way to know things are happening is to watch the airlock. When you see it bubbling that means CO2 is escaping, and the beer is fermenting. If you were to take off the lid at this point you should also see krausen (foam) that forms on top of the beer. Some beers will create more foam than others, so don’t panic if it doesn’t look exactly like the last batch you made.

The entire fermentation process can take as little as 12 hours to as long as 4-5 days for your typical ale. What we’d like to see as brewers is a quick start time with a long finish time. This would mean that we had plenty of active cells to begin with that remained healthy during fermentation, and completed the job as they we supposed to. Don’t worry if you don’t see this situation because like I said this would be ideal. More realistic is a 24-48 hour start time with 2-4 days of fermentation time total.

We’ll get into how to improve your fermentations in future posts, but we know when folks are new at something you have to give some basic information of what to look for, and how to do it. Just like any other hobby there are things people will learn as they do the hobby more. It is easy to produce a great tasting beer from batch number one, but you will only get better from there. The more you brew the better you will become. So, brew often.