How did we ferment before the Fermzilla Unitank?

At first we were using two SS brewtech buckets of 27L and two fridges which we modified to climate control chambers. If you want to find out how we build those, read it here! Although this worked perfectly, we wanted to start with pressurized fermentations! At second we wanted to scale up our fermentation capacity. Because after we organized an amazing beertasting with family and friends, we found out that we drank all our craftbeers.. So we decided we had to scale up our fermentation capacity and add the options of being able to do pressurized fermentations.

How we scaled up to a Fermzilla with a self built climate control system!

After some research we decided to use a climate controlled 55L Fermzilla Conical Unitank. At first we almost bought a famous stainless steel Unitank but than we decided to gain some experience with a pressurized unitank. Secondly we had to build a different climate control system for the Fermzilla. We bought the Fermzilla’s and we decided to go for it. Although it was quite some work to figure out all the parts we needed, but it also was a lot of fun. Once we got these fermzilla’s set up the real challenge started!

It’s been quite a ride to get these Fermzilla´s ready for fermentation. So don’t underestimate it when you are thinking of buying a Fermzilla Unitank. We bought two of the 55L conical unitanks from Kegland. They also offer Fermzilla fermenters with a smaller capacity such as the 27L unitank version. The reason we wanted to use these 55L Fermzilla´s is because we want to be able to do pressurized fermentations in the future. Instead of buying an expensive stainless steel unitank we found these were the more affordable option. So it was definitely worth the try!

Why do we want to ferment under pressure and why we choose this Fermzilla?

The main reason why we wanted to start with pressurized fermentation is that we are going to brew more hop forward and aromatic beers like India Pale Ales (IPA), New England India Pale Ales (NEIPA) and some fresh experimental homebrews! These NEIPA and IPA styles are very vulnerable to oxidation and that is what we would like to prevent ofcourse! Besides that we wanted to scale up a bit. The current fridges functioning as a climate control system is working great but the 55L Fermenters don’t fit in the fridges so we have to adapt our cooling system as we are scaling up. An climate controlled Fermzilla Unitank is what we need, second challenge accepted!

Climate controlled Fermzilla Unitank.

What are the benefits of fermentation under pressure?

Fermenting under pressure suppresses off-flavors, the upper limits for temperature are higher. Fermenting at higher than normal temperatures produces many off-flavors. These include higher alcohol and solvent-like flavors. Under pressure, brewers can ferment warmer. This speeds up fermentation without the risk of off-flavors. By fermenting under pressure, beer can be fully carbonated in the fermenter – completely naturally!
When brewing hoppy beer, the goal is to capture all of the delicious volatile hop aroma’s. During fermentation and Co2 production, hop oils are driven off as the gas escapes the fermenter. Capping the fermentation and fermenting under pressure keeps hop oils in the beer for maximum aroma and flavor. Beer fermented under pressure does not produce a large krausen, the foam on top of fermenting beer. Because of this, less headspace is required in the fermenter. So you don’t need to worry about a messy or explosive fermentation.

Climate controlled Fermzilla Unitank.

Tools and equipment you need

Buying the right equipment can be quite challenging. To get the Fermzilla conical unitank into pressurized fermentation you do need some additional accessories. Buying the additional parts that are needed can be costly. Although, the KegLand company does a great job on keeping you out of trouble with their video tutorials. At the end of this blogpost you will find anything you’ll need to buy to create your Fermzilla setup at home! We made you a shopping list, easy as that!

How to climate control the Fermzilla Conical Unitank?

As we mentioned before the Fermzilla 55L doesn’t fit in our climate controlled fridge. So we had find a way to control the temperature. If you’ve been brewing craft beer for a while you probably figured out yourself that climate control during fermentation and lagering is one of the most important steps in brewing. We choose to install a temperature twister and use an external water/glycol cooling system. In order to climate control the Fermzilla Unitank we had buy the accessories we needed and think of all the steps we had to go through. Follow these steps to setup your climate system:

STEP 1: Transfer the beer from the kettle to the Fermzilla Unitank.
We needed an external pump and hoses to pump our batch of beer into the fermzilla unitank. As the tanks are placed higher this was a good solution to us. We recommend to put them on a lower level to solve this problem.

Fermzilla unitank

STEP 2: Cool down your wort in the fermenter after brewing.

We needed a cooling coil inside of the Fermzilla and an external cooling system. We decided to use a freezer, in the freezer we put a bucket with a mix of glycol (food grade 99,5%) and demineralized water. Now we had to get the cold liquid to the spiral in the fermenter. First we removed the lid of the freezer and built a wooden frame between the lid and the freezer itself. After that we were able to drill holes through the wood for the hoses. We put a pump in the bucket with the cold liquid, connected the hoses to the pump, through the wood and connected it to the coil. Fixing the leaks between the hoses was a challenge because we had to convert from a 25mm hose to a 10mm hose. For this we used different convert parts and in the end we had it working. Don’t forger isolating the hoses because it will limit your cooling capacity.

STEP 3: Control temperature during fermentation, cooling and heating
As we wanted our temperature controller to be remote controlled we chose to use the Inkbird Wifi thermostats. We have great experiences with these products with the other climate controlled fridges. The best thing is that we can control the fermentation on our smartphones, anywhere, anytime!

STEP 4: Pressurize after aerating and control pressure
The CO2 bottles we use for carbonizing the beer and doing a pressurized transfer are the small ones from the Soda Stream brand. They are small, lightweight and easy to use. They work perfectly! You can always buy a big CO2 tank at your local brewstore.

StTEP 5: Remove yeast and trub after primary fermentation
Underneath the fermenter there is a small yeast container to collect or remove the trub after primary fermentation. Also we used this to add a dryhop and to harvest yeast for our next batch. The butterfly valve is used to open or close the collection jar.

STEP 6: Cold crashing the unitank
After lagering we cold crash by setting the inkbird to 3-5 degrees celsius. This means the pump will start and pump the cold liquid through the coil until the wort is cold enough.

STEP 7: Transfer the beer to kegs or bottles
Transfering the beer to kegs needs to be done using a forced carbonation method. This way we can purge the beer from the Fermzilla unitank into the corny kegs. Besides kegging the beer we can directly fill bottles using a counter pressure bottle filler. Therefore we are installing a Boel Itap Counter Pressure Bottle filler as soon as possible!

We filled our first Climate controlled Fermzilla Unitank!

After brewing our blonde beer we were able to fill up the Fermzilla for the first time. We filled it up and it went perfectly. After we continued chilling through the cooling coil because the wort was still 30 degrees. It went smoothly from 30 degrees to 22 degrees and this is when we pitched the yeast.

The last step was closing the lid and to pressurize the unitank. The first Co2 escaped immediately so we had to take the lid off again and check all the connections and fittings. We found out that there were some leaks we had to fix. We checked them all and were able to fix it. Then we tried one more time and it worked! The only thing for us left to do now is to follow the fermentation through our brewbrain float hydrometer and adjust the temperatures through our inkbirds. This way we can live track our fermentation in our BrewFather App and adjust the temperature using the WiFi Inkbird thermostats, awesome isn’t it?

Climate controlled Fermzilla Unitank.



  • We were surprised about the quality of their duo tight fittings which we used to connect all the hoses.
  • The Fermzilla’s seem low quality but it surprised us how ‘easy to handle’ they are.
  • Using them under pressure works a lot easier than we thought.
  • Easier and faster fermentation because of the pressurized fermentation. You can ferment at higher temperatures without gaining a lot ester production in your beer.
  • Rack of the yeast trub that settles out after primary fermentation, you can leave the beer in the same tank so less cleaning and transferring!
  • Brewing hop forward styles is very beneficial with the fermzilla, keep the aroma’s pressurized and an O2 free dry-hop using the container.
  • It allows you to do an oxygen free transfer to a keg or bottle directly from the fermenter using a iTap counter pressure bottle filler from BOEL-company.
  • Get the isolation jacket when you are not using a climate controlled fermentation chamber.


  • The hoses have specific sizes and don´t fit with other tubes and connectors. We had problems connecting the temp twister to our cooling system.
  • The dump container gets stuck very easily, unfortunately we broke two containers because of this. The strap-tool is not that good, you lack space and grip to give it a good twist. Also, things will get messy removing the container.
  • Limited time to use the tank, until expiring date, this means you have to do a quality check for the safety of doing pressurized fermentations
  • You have to buy quite some accesories to get all the benefits of the fermzilla unitank, wich can add up to the costs.
  • Be gentle with your PET-tank, don’t use sponges because this will leave schratching marks on your tank wich can house bacteria of leave trub behind.
  • The fermzilla conical unitank valves are very hard to dismantle for a hard clean.
Fermzilla dry-hop

Tips & Tricks using the Climate controlled Fermzilla Unitank.

Make sure you do a test run with the Fermzilla before filling it with your homebrew. You need to be sure that there are no leaks in the fittings and connections otherwise you can not pressurize the unitank. Which means you can not do a pressurized closed transfer when the fermentation is finished.Sometimes thinking out a plan is a lot easier than performing it, which is fine but then set a realistic timeframe as well. This project is awesome but time consuming!

Shopping list


Recently Kegland released a new upgraded version of their fermzilla tanks. You can find more information on these Fermzilla Unitanks here. The tanks are available 27L and 55L capacity. Until now we have only read online about their improved product. At first, this looks promising. The main upgrades to the system is replacing the trub/yeast container system with Tri-clamp fittings. This will prevent the problem of breaking containers and will make cleaning and dismanteling the fermzilla unitank a lot easier! Also, you don’t have to use the straptool anymore, thank god! At second they have released a new dry hopping kit do to oxigen free dry-hopping and some new quick disconnects. We also recommend to buy these new disconnects suitable with the duotight fittings.

However, we would like to get our hands on one of these new and improved Gen 3 unitanks. So we offered to write a blog article and do video review on the product but unfortunately we haven’t got a reply.


If you have made it to the end of this blog, thanks for reading! At this point, we would only recommend to buy the Fermzilla 3th generation with the tri-clamp upgrades. It might be a little more expensive, but it is more durable, better to clean and it will save you a lot of broken or stucked containers. Tri-clamps are easy to manage, so this is a big improvement compared to the use of the well known hated fermzilla strap tool.