The fermentation is one of, if not the most important parts of the homebrewing process. It is where many key stages take place, but is also where a lot of things can go wrong. A lot of it though comes down to being patient and prepared. Yet there are ways you can affect the process, which much of the time comes down to how your fermenter is treated. Understanding how to use it is the main way you can make sure your homebrew is successful.
The most common mistake I see people make with homebrew is temperature. At every stage it is possible to mess up, and when it goes wrong can have seriously damaging effects. Luckily at the fermentation stage it is not as risky, unless you somehow managed to boil it again or freeze it solid. Yeast will start to die past 30°C, but can become inert when lower than 23°C. So we recommend keeping it between this range. An airing cupboard is a great choice for this, but if you house is warm enough it can be stored anywhere. Depending on the season this might change. Your kitchen might be warm enough in summer, but come winter especially at night it may drop too low. It isn’t a bad idea to keep a thermometer around your fermenter just to make sure everything is okay.
Patience is a virtue, and with homebrewing it can be very hard. For your homebrew to start fermenting it can sometimes take up to a day, usually it will be going the morning after. Even when fermentation has started it can be quite hard to tell what is happening in your fermenter. It will occasionally bubble but even this won’t always be a constant. For you to see it bubble pressure has to build up and fill the fermenter. To release this pressure your air lock allows the gas to escape. Some beers will be very active, this creates a lot of gas so near constant activity. Others are much slower and will only bubble on occasion. Smaller batches tend to bubble less.
Infection is another big issue. Anything getting in your beer has a good chance to add an off or unwanted taste. It can even completely spoil your beer. Your fermenter must be sterile before you add anything to it. This makes it is a good idea to sterilize it right as you are mashing or boiling your homebrew. This leaves no time for it to get infected. But you might want to give your fermenter a regular clean anyway, especially if you store it in a shed or loft.
Some brewers will recommend cracking open the lid for a quick look. It is unlikely to ruin your beer, and it does give you a quick chance to have a smell to see if anything is off. We don’t recommend doing this though. First it creates a chance for infection, but the bigger issue is sometimes perfectly fine beer can just smell a bit off. Certain beers can create compounds like sulphurs, these often give off a bad smell yet they will disappear over time and not harm your beer at all. So making sure your homebrew stays sealed is probably best. On our fermenters you will see the top lip, a ridge and a second lip. It is this ridge which is most important as that is where the bucket is sealed. You’ll know the bucket is sealed right when you here a sound as it clips over the ridge. So if you do decide to unseal it makes sure it is properly pushed back on.
The only way to know exactly what is going on in your fermenter is using a hydrometer. A hydrometer allows you to test the gravity of a liquid. Water is denser than alcohol so you’ll see a change as more is created. The lower the number, the more alcohol has been created. Though you don’t want to be constantly taking samples either, you’d end up wasting a lot of the beer. Even if you sterilized your hydrometer it isn’t worth adding this liquid back. A hydrometer is best used when you think the beer is ready for bottling, but if you are worried about the state of a homebrew it won’t have any negative effects.
What makes the fermentation stages tricky is to some degree you are pretty removed from the process. You can certainly attempt to tweak every little variable to ensure success, but the actual fermentation is pretty much out of your hands. Being prepared is the best thing you can do, but sometimes you just have to let the process take its course.