Many homebrewers like to take advantage of a process called “secondary fermentation,” and claim that it improves the quality of their homebrew beer. Secondary fermentation, also known as two-stage fermentation, is simply transferring (“racking”) your homebrew from one fermenter to another. The optimal timing as to when to start the secondary fermentation is up for some debate, but it is about midway through the fermentation process. But why go through the trouble? Is putting your beer through a secondary fermentation really necessary. What are the benefits?
The Pros of Secondary Fermentation for your Beer
Here are a few of the benefits of secondary fermentation:
- It gets the beer off spent yeast sediment. After two or three weeks, yeast starts to break down and contribute off flavors to your beer. Most homebrewers don’t ferment their beer long enough to cause any noticeably problems, but for those who choose to do a longer fermentation, racking the beer into a secondary fermenter or carboy is highly recommended.
- It allows the beer to mature. Time allows the malt, hops, and yeast flavors to blend together and balance.
- It improves clarity by reducing the amount of sediment in the finished beer. Putting your beer through a secondary fermentation allows time for more yeast, hop trub, and protein to fall out of the beer. Adding a fining agent, such as gelatin, into the secondary fermenter can aid in this process significantly.
- It gives the homebrewer an opportunity to “dry-hop” — or “dry-spice” — their beer. Dry-hopping is just adding hops to the secondary fermenter, which contributes hop aroma to the beer. You can also take this opportunity to add spices, flavorings, wood chips, or other additives to your brew.
The Cons of Secondary Fermentation for your Beer
There aren’t many disadvantages to using a secondary fermentation, but they’re worth considering:
- It takes a more time and effort. Yes, it takes some time to transfer or rack your beer to a secondary fermenter. How long it takes varies depending upon your set-up, but usually the time it takes to transfer is much shorter than brew day or bottle day.
- There’s a risk of contamination. By opening your fermenter and passing your beer through a siphoning hose, you risk bacteria or wild yeast getting into your beer. But, as long as you practice good sanitation, you should be fine.
- Potential to lose hop flavor. Hop flavor degrades over time. In most cases, a few weeks won’t make a difference, but if you’re brewing a very hop-forward beer, the length of the fermentation period should be considered.
How to Transfer Your Beer for a Secondary Fermentation
To transfer your beer to a secondary fermenter, keep in eye on the bubbles coming out of the airlock and wait until the fermentation slows down (4-5 days). Clean and sanitize your secondary fermenter and transfer tubing, then add the beer to the secondary fermenter – usually a carboy – by siphoning. Re-seal with an airlock. In 7-14 days, bottle or keg your beer as you would normally.
Do you use a secondary fermentation when you homebrew? When do you start yours? How long do you leave it in the secondary? Leave a comment!
Til next time…Cheers!
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David Ackley is a beer writer, brewer, and self-described “craft beer crusader.” He holds a General Certificate in Brewing from the Institute of Brewing and Distilling and is founder of the Local Beer Blog.
I always second ferment my beers; much more clear, less sediment in the bottles; I’m a wino first, so very used to racking. Also likelihood of exploding bottles is very small (haven’t had one yet).
Having been a wine maker for 40 years (with a 25 yr break when I moved to S.Cal.), I have always had a leaning for racking – referred to as secondary fermentation from my winemaking daze. Racking is not a requirement, but I don’t see how dead and decaying yeast cells will add to efforts to create a beer your friends enjoy. However, if you just aren’t into the flavor as much as the alcohol, you should be making something other than beer – like brain numbing blinding moonshine!
Wine maker first here too and I like the idea of less work and no racking. I have made dozens of batches of beer now and haven’t racked a single one to a secondary. Usually I let it sit in the primary and age for about a month, that lets it get pretty clear, crystal clear some batches. The last batch I kegged was only 2wks in the primary, an the last batch I just bottled was sitting in the primary on its own yeast cake for 2 full months and both are delicious. I was worried about that one, always reading about the rotting yeast giving it off flavors. Tasted just fine. Racking beer to secondary is just an extra step not needed, imo.
I’ve brewed a few dozen batches, searching for the perfect IPA. The most recent half dozen or so I have racked and dry hopped in a secondary fermentation. A week for the first, a week for the second, then rack into the bottling bucket with the priming sugar. I have noticed it is much clearer and I’m getting closer to hoppiness I am looking for.
I used the little brown keg a few times and then moved to a little big mouth bubbler and 1 gal cider jugs for secondaries since that’s what the small kits come with now. I can leave it in the secondary longer and have less sediment when bottling. Bottle conditioning adds a good amount of sediment anyway but I still think the secondary helps keep it lower than without it.