Is secondary fermentation really needed?
Ask one brewer and the answer is “Yes Always”!
Then ask another brewer and the answer is “No Never”!
One of the great ongoing debates that continues to be a topic in the home beer brewing industry is whether secondary fermentation is beneficial to the finished beer and serves any useful purpose, or if it is a complete waste of time and energy.
Many homebrewers who have been crafting their own beers, claim that the risk of contamination and oxidation is far greater than the reward of doing a secondary fermentation. Then brewers on the other side of the fence say the risk is totally worth it, because it improves the overall taste and appearance of the beer.
We are here to give you some information about two-stage/secondary fermentation, with reasons why you might want to do it, or why you want to skip it altogether.
- 1 What Is Secondary Fermentation?
- 2 Is Secondary Fermentation Necessary For Your Home Brew?
- 3 When To Transfer The Beer From Primary To Secondary
- 4 How Long Does Secondary Fermentation Take?
- 5 Is An Airlock Required During Secondary Fermentation?
- 6 Exposure To Oxygen
- 7 Benefits Of Secondary Fermentation & Why It's Important
- 8 Drawbacks Of Secondary Fermentation
- 9 Final Say
What Is Secondary Fermentation?
For a much clearer beer and a better overall flavor to the finished product, many beer brewers and the manufacturer’s of beer ingredient kits often recommend a “secondary” or “two-stage” fermentation.
After the primary fermentation phase is complete and the yeast has done most of it’s job by eating and converting the sugars to alcohol, choosing to do a secondary fermentation by transferring the the beer from the primary fermentation bucket, to a second vessel can make for a better finished beer.
With a secondary fermentation, you are essentially removing the beer from the yeast cake and sediment that has gathered at the bottom of the fermenter during primary fermentation.
This extra step in the beer brewing process is intended to help the beer “age” and become “clearer” as the bits of yeast that are still floating in suspension settles to the bottom of the vessel once again.
Is Secondary Fermentation Necessary For Your Home Brew?
If you are new to homebrewing, making a lager is not really recommended for your first brew, so you will more than likely begin with some sort of an ale using a pre-packaged beer ingredient kit.
Within the instructions of most of these beer recipes, they tell you that primary fermentation will usually take between five and seven days, and then have an optional secondary fermentation, where the beer will sit for another week or so.
Even though the beer can be bottled directly after primary fermentation, doing a secondary is often recommended for a clearer beer and to prevent off-flavors from the beer sitting on the trub.
Also if you are brewing with fruit, adding the fruit to a secondary vessel is the preferred method for most home brewers.
If you think that you will want to do a secondary fermentation on your first batch of craft beer, or any following batches of beer, you will need to purchase an additional fermenter, or make sure that the beer brewing kit that you buy already has one included.
You can check out which beer kits contain an additional carboy for secondary fermentation on our beer kit review page,
When To Transfer The Beer From Primary To Secondary
It is recommended that you wait to transfer the beer to a secondary fermenter until primary fermentation has stopped, which should take between five to seven days.
It is best to use a hydrometer to take a gravity reading with a small sample of the beer to confirm that fermentation has completed. The lack of bubbles in the airlock is an indication that fermentation is slowing and nearing the end, but doesn’t mean it is finished.
It won’t hurt to wait a day or two longer to transfer the beer, while waiting for the leftover yeast to clean up any additional byproducts which can add to some undesirable flavors to your beer.
After racking to the secondary, it’s normal that you might see a little bit more activity from CO2 that is being released from the beer being disturbed during the transfer.
How Long Does Secondary Fermentation Take?
Even though it is called secondary fermentation, it is more of a “conditioning” step in the overall beer making process. By the time primary fermentation has finished, the yeast has pretty much finished it’s job, and most of the alcohol has already been made.
If you choose to do the secondary fermentation, the recommended length of time for secondary can be anywhere from one week to six months, depending on the style of beer.
Beers that have a lower original gravity, like pale ales, will only require a week or two, where the beers that have a higher original gravity, like stouts, and barley wine, will be much longer.
Is An Airlock Required During Secondary Fermentation?
Since fermentation is technically finished by time you rack to a second vessel, many homebrewing experts claim that an airlock is not needed.
Even though the rigorous fermenting stage is over and most of the yeast cells are dead, there are still some active yeast that are active and looking for something to eat.
During this time, there is often a small amount of CO2 that will still be produced, which can still build up pressure in the secondary vessel. This is why still using an airlock is recommended.
Exposure To Oxygen
One thing that every brewer, whether it’s a commercial brewer in a mega brewery or an amateur home brewer, is to avoid the introduction of oxygen in their finished beer.
Before fermentation, it is actually good to stir or aerate the wort before pitching the yeast. Oxygen is needed for the yeast to grow while it does it’s work during primary fermentation.
But after the primary vessel is sealed and an airlock is installed, any oxygen that makes contact with the beer from this point on can end up being the cause of many off-flavors in your beer.
This is one of the main reasons why some home brewers avoid this step all together.
Benefits Of Secondary Fermentation & Why It's Important
Unless your beer recipe specifically calls for secondary fermentation, it it probably not needed. But even if your recipe does not require it, there are quite a few reasons to do a secondary fermentation anyway.
Avoiding Off-Flavors In Your Beer
Removing the beer from the primary fermenter which has accumulated a layer of dead yeast and other particles can keep your beer from picking up unwanted flavors from these sediments that have settled at the bottom of the vessel during the long fermentation phase.
A Clearer Finished Beer
Many of the beer styles that you will make at home with not have the clarity that you will find in a commercially brewed beer.
But if you want the clearest beer possible, racking the beer to a second fermenting bucket or glass carboy, will give more of an opportunity for any remaining trub and yeast that is still in suspension time to settle, will give your beer a much more clear appearance.
Better Overall Flavor
Allowing the beer to sit for another week or two will give the beer more time to mature and “age” which can give the beer better flavor, and better balance.
Adding Additional Ingredients
During the secondary fermentation phase is where you will most likely want to add any additional ingredients like spices and fruits. This is also the time where you can also do some “dry-hopping“.
Drawbacks Of Secondary Fermentation
As we stated earlier in this post, many beer brewers avoid secondary fermentation unless it is absolutely needed for the type of beer they are brewing.
Many advanced brewers really don’t see much of a benefit, and simply isn’t worth the extra time, the risk of infection, and possibly dumping five gallons of once perfectly good beer down the drain.
Chance of Infection
The most important thing in the beer making process, is to keep everything that comes into contact with the wort, and eventually beer, completely sanitized.
Every extra step that is taken during the brewing process, and each time you open the lid of the bucket, you are introducing oxygen, bacteria, and contaminants into the beer, increasing the chance of ruining and infecting your beer.
It's an Extra Step
Besides the chance of contamination, many homebrewers want to try their creation as soon a possible and don’t want to wait even longer.
If you to enjoy your beer sooner than later, and unless your recipe call for it, you might want to skip the step, which will add another 7 to 14 days before you are ready to bottle.
Requires More Equipment
Ideally you want to use a glass carboy for secondary fermentation instead of a plastic bucket, and many kits do no include the carboy as part of the package.
Many first time homebrewers buy the least expensive beer kit that just has the minimal equipment needed to brew a standard batch of beer, so you must buy a glass carboy separately, or a beer kit that has one already included, which will also increase the overall cost of your brewing equipment.
So should you do a secondary fermentation or not? What it all comes down to is what do you want to do? If you are brewing a low-gravity beer, you probably won’t notice much of a difference in the final outcome.
But as a homebrewer, it is definitely something you should learn to do, and become familiar with the process. I personally have done a secondary conditioning phase on more than half of every batch of beer that I have brewed, and not once have I ever had my beer get contaminated or infected.
That doesn’t mean that you will never have infected beer because you don’t do a secondary fermentation at all, and it doesn’t mean you will infect your beer if you do.
Yes there are some risks involved every time you introduce oxygen to your beer, but if you follow the directions, and keep all your equipment clean and sanitized, you shouldn’t have any problems.
What it comes down to is your personal preference and what you are comfortable with. If you do that’s great, and if your don’t, that is great too. The only way to know for sure is to both and see what you end up with.
So if you are interested in giving the two-stage fermentation a try, just get an additional glass carboy (new or used) if you don’t have one already, and give it a shot. That will be the only way to see for yourself if it is worth the time and effort or not.
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