When you are first learning how to make beer, you will see information about primary fermentation and secondary fermentation. It is common for new brewers to wonder just how long it takes to ferment beer. The answer can vary, and there really isn’t one right answer. Many factors influence this, and it comes down to whether you will secondary ferment or not.
First of all, secondary fermentation is actually not fermentation. You do not rack your beer to secondary until after it has completed the fermentation process in the primary. The secondary fermentation is done to clarify and condition the beer, and no actual fermentation takes place. The clarification and conditioning can also be done in the primary fermenter as well. Sound a little confusing?
One reason those just starting to learn how to make beer get confused is because of experiences with kit brewing. Often, these instructions will tell you that your beer will be done fermenting in a week. Although this is possible, this isn’t always true. It is also possible that fermentation is not complete, which can lead to bottle bombs. Or worse, you can experience what is known as a stuck fermentation, in which fermentation stops mid way through and does not complete. This will lead to bad tasting beer.
The key to remember when learning how to make beer is that allowing your beer time to age makes for better beer. It is important to let your beer completely ferment before moving on to the next stage. The simple answer for how long fermentation takes is about 10 days. The time it takes depends on the lag time–how long it takes fermentation to start after the yeast has been pitched. This varies and depends on the type of yeast used, and the condition and age of the yeast. Lag times can be as short as an hour or two, and on up to 72 hours.
As you are learning how to make beer, you will likely read many varying opinions on how long to ferment in the primary. Just because fermentation completes in 7-10 days does not mean your beer is ready to drink. Chances are, it isn’t ready to do anything with just yet. Remember, beer likes time.
Another common mistake among new brewers is not allowing the beer enough time to age in the bottle. You don’t want to drink a beer right after bottling it, or within the first couple weeks of bottling because it is not yet carbonated. Some kits may tell you that your beer is ready to drink after a week in the bottle, but you are better off waiting a couple weeks, as your beer will taste much better.
Then there is the issue of whether or not to secondary ferment. Many home brewers skip this altogether, and instead keep the beer in the primary for a few additional weeks. The secondary clarifies and conditions the beer, but you can also accomplish this in the primary by leaving it in there for a couple additional weeks. This keeps you from having to rack the beer to the secondary and exposing it to the air, which increases the risk potential for contamination.
So why then would you secondary ferment? If you are brewing a lighter colored beer, then the secondary might be better to help with the clarity. If you were to add fruit to your beer, then you will want to do this in the secondary, not the primary. Also, if all you have is a bucket and a carboy, then racking to the second will free up the bucket to brew another batch. This way you will constantly have home brew on hand. On the flip side, you could just purchase an additional fermenter to make this happen.
As far as how long to leave the beer in the primary of you do not secondary, opinions differ. The easy answer is not to bottle right after 10 days. You could if you really wanted to, but the additional time in the fermenter will make your beer much better. In researching this on forums, you will see numbers like 1-2-3 or 3-2-3. These indicate the number of weeks in the primary, secondary and bottles.
If you bypass secondary, then look to leave your beer in the primary for 3 to 4 weeks, and an additional 2-3 weeks in the bottles. Sure, the kit instructions don’t tell you to wait that long, but it will be worth the wait. It’s tough, especially on your first batch, to wait that long to drink the beer, but it will greatly improve your beer.
To avoid the wait, make sure to have an additional fermenter handy so you can always have another batch of brew going, and that will keep you stocked with home brew while waiting on the next batch. Or, make the leap into kegging and cut down on the wait time.