Everything to Know About Secondary Fermentation

Secondary fermentation might seem like a complex idea followed by a more complex procedure. However, I will break it down so you understand what secondary fermentation is and how to use it to brew cider, mead, beer, kombucha, wine, etc.

When brewing, I don’t always practice traditional secondary fermentation. Though, when making beer, secondary fermentation is a tried and true way to make delicious hoppy IPAs, or simply adding more flavor to your herbal beers.

You are going to learn what primary vs secondary fermentation is, how to implement secondary fermentation, when to do it, and tips on a successful secondary ferment for beer, mead, wine, cider, etc.

This post is all about secondary fermentation.

Primary vs Secondary Fermentation

As we might be aware, fermentation is the act of yeast eating sugars with the byproducts being alcohol and carbon dioxide. Once we break that down we see there is a difference between primary fermentation and secondary fermentation.

The Phases of Fermentation

Adaptation. Adaptation is the lag phase when the yeast cells begin to blend into their environment. No yeast activity is seen yet in the fermenter; it is a relatively short period (12-48 hours).
High growth phase. The yeast have acclimated to their environment and now they begin their ultimate job: eat and reproduce. Eat the sugars and make more yeast cells!!
Maturation / Conditioning. Once most of the sugars are eaten, the yeast cells essentially go into hibernation and the beer begins to “condition”. This is when the flavor profile begins to develop.

Primary Fermentation

Primary fermentation is the initial life of yeast cells in your brew (wine, cider, mead, beer, etc.). Depending on your ferment, primary fermentation can last a couple of days, like for wine, to a few months, like a lager.

The rule of thumb is primary fermentation ends when the high-growth phase ends. In other words, when your airlock bubbles begin to drastically slow down, then, you are finished with primary fermentation.

Secondary Fermentation

You can implement secondary fermentation right after the high growth phase and before maturation/conditioning is complete to add flavor, dimension, elegance, and cleanliness to your ferment.

In all, the main objectives for secondary fermentation are to add more flavor and dimension and/or to create a cleaner, crisper beverage.

For some ferments, like wine, secondary fermentation is arguably the most important part of the fermentation process. Specifically for commercial wineries, secondary fermentation occurs in the barrel.

Wine is left in the barrel for a few weeks to develop and balance out flavors. For example, a chardonnay that sits in oak barrels soaks up the oak flavors leaving the chardonnay with a hint of oak. That is just one example of how powerful secondary fermentation is.

On the other hand, beer secondary fermentation usually lasts about one week and is a prime time for dry hopping or adding other herbs and spices to round out the flavor.

What is dry hopping?

Dry hopping is when brewers add more hops to the secondary fermentation to add more flavor and aroma. Usually, the hops added are the same hops in the beer to excentuate and embolden those specific flavors and aromas.

Another Bonus to Racking into Secondary Fermentation: Cleanliness

Another important aspect that SF allows is the “cleaning” of your ferment. When you rack your beer or cider into another fermentation vessel, you pull it off the sediment layer on the bottom of your vessel.

The sediment layer in beer making is huge due to hop sediment. Thus, secondary fermentation can not only benefit the flavor but also the cleanliness of the beer; aka no sediment!

Now, let me clarify something! You can rack your ferment into secondary without adding hops, herbs, or spices. You can simply rack your ferment to create a cleaner finished drink.

How to Implement Secondary Fermentation

Secondary ferments are quite simple to do. In fact, there lies so much potential for elegant flavor in secondary fermentation. Let’s dive into how to implement this!

What equipment you need:

Your ferment: beer, cider, kombucha, mead, wine
Siphon hose
Star Sans
Second fermenting bucket or one-gallon fermenter (depending on the size of your ferment)

How to rack your ferment into secondary:

1. Gather all equipment and sanitize your siphon hose and second fermenter!

2. Be extremely gentle with your ferment when you move it around. You want to keep the sediment at the bottom as intact as possible.

3. Move your ferment to a countertop with the second fermenter on the floor.

4. Gently place your siphon hose into your primary fermenter. Allow it to slowly make contact with the bottom of the vessel.

5. Place the end of the siphon hose into the second vessel, making sure it does not slip out easily. When the liquid begins to flow, the hose likes to fly around!

6. If you are using this siphon hose, pump the siphon a couple of times until the liquid begins to flow. I use a generic tube, which is a different, more challenging, technique and I would recommend the siphon hose with the pump!

7. Allow the ferment to completely transfer into the new vessel. Note: there will still be some liquid left over that is swimming with the sediment.

8. Place your dirty fermenter and siphon aside, and place your new vessel on the counter.

9. Depending on your goals, you are either done with secondary fermentation or ready to add herbs, spices, hops, etc.

10. Add in your flavorings: hops, herbs, spices, etc.

11. Place your secondary ferment in a dark cool place, between 70-75 degrees F, or what is specified in your recipe.

12. Depending on your ferment after a week or so, you can move on to bottling!

How Long to Leave Your Beer, Cider, Mead, and Wine in Secondary

Every ferment is going to be different when it comes to the fermentation process. Some ferments take months while others a couple of days.

To know exactly when your ferment is done fermenting in secondary, proper practice is to use your hydrometer. This will show you exactly when all sugars have converted to alcohol.

Though, when I am brewing beer or cider I can gauge the fermentation on the activity in the airlock and the time in the fermenter. More times than not, that will yield the correct time to stop the fermentation. When the airlock begins to slow, that is usually a good indicator that the high growth phase is ending.

Additionally, use your taste buds! As your ferment begins to develop you will be able to gauge the direction you want to take. Either pulling it out of fermentation adding more herbs, or allowing it to sit longer.

Time in Secondary Fermentation per Ferment Style: General Rule of Thumb

how long to leave beer in primary fermenter

Secondary fermentation beer

Usually, beer ferments for two weeks. That is one week in primary and one week in secondary.

Secondary fermentation wine

Wine also lasts in secondary fermentation for one to two weeks. However, you may leave it in secondary fermentation for three to four months!

Secondary fermentation cider

Typically, cider lasts in secondary 2-4 weeks but depending on your goals you can leave it in secondary for 2-4 months to further clarify and balance out!

Secondary fermentation mead

*I am not an expert in mead making*, though, Pascal Baudar’s book The Wildcrafting Brewer mentions that a mead’s full fermentation can take months. But, one could also simply ferment mead for 2-4 weeks and enjoy. It depends on your intentions and the recipe you are using!

Secondary fermentation kombucha

*I am not an expert in kombucha making*. When my partner made kombucha at home, we learned that the longer you leave it in secondary fermentation the more vinegary it gets. So, the rule of thumb is 2-14 days in secondary, however, taste as you go!

As you can see, this is an art. It is up to the creator what he/she wants to create and what expression he/she wants to portray. There is no one way to ferment, so explore and learn as you go!