Pressure Transfers

FermZilla All Rounder 30L & 60L | Pressure Transfers

Advantages Of Pressure Transfers

One of the main advantages of a pressurisable FermZilla is the ability to transfer the finished beer into a keg under pressure. This enables a closed transfer with neither the keg nor the FermZilla needing to be opened so that it is possible to all but completely eliminate the risk of oxidation/O2 ingress.

This is a fantastic boon for the avid homebrewer - avoiding oxidation when transferring helps all beers, especially modern hoppy styles such as NEIPAs.

Whilst fermenting under pressure can be performed using just the CO2 generated during fermentation, most pressure transfers will require a source of CO2 and a regulator. Options for this include a refillable 2.6kg or 6kg CO2 Cylinder and a MK5 Regulator. If space is limited a KegLand Branded Sodastream cylinder and a Mini 360 regulator are great options.

There are two easy ways to transfer your beer under pressure. The first step is to sanitise and purge the keg to be filled with CO2.

Sanitising and Purging Kegs

1. Once the keg has been cleaned and rinsed, completely fill the keg with sanitiser solution such as StellarSan diluted to the correct ratio

2. Invert the keg for 120 seconds, then put the right way up to make sure that all surfaces some into contact with the sanitiser

3. Connect the keg to CO2 at around 10psi. Pull the PRV a couple of times to purge the small amount of headspace

4. Next we need to push the sanitiser out of the keg. Ideally connect the full keg to an empty, clean keg. Connect the two Liquid (Out) Posts with a short length of line. Put a Spunding Valve on the Gas Post of the empty keg. Use this to vent pressure in the empty keg at around 5psi. The pressure differential will push the sanitiser from the full keg to the empty keg

5. If you do not have an empty keg then the sanitiser can be transferred into any vessel of around 20L, or simply emptied into the sink.

6. Once the transfer is complete, the empty keg will now be sanitised and purged of O2. It will also have some residual pressure which is ideal for transferring from the FermZilla

A FOBS (Foam On Beer) detector can also be repurposed to detect sanitiser rather than beer - check out this video. It is a great way to automate this process.

Using a FOBS to automate purging kegs

Transferring Finished Beer Under Pressure

Before transferring the finished beer into a keg, we want to ensure that it is completely fermented. Taking a gravity reading over three consecutive is is the best way to ensure this. If the reading is stable for three consecutive days we can be sure that the fermentation is finished.

Cold Crashing Before Transfer

Before transferring the completed beer, it is ideal to cold crash the beer.

Cold crashing is quite simple if you have temperature control for your FermZilla. Simply set the temperature to -1-2°C (or as low as you can if it will not go this low). Once the desired cold crash temperature has been achieved, leave the finished beer at this temperature for 2-4 days. This will 'cold crash' the finished beer. Cold crashing helps a lot with getting solids such as hop matter, yeast and other solids in suspension to drop out of the beer. It also helps to compact the trub in the fermenter. Cold crashing is therefore very beneficial for transferring a clean beer into the keg, minimising trub in the keg.

If you cannot cold crash that is OK. The integrated filter on the floating dip tube will assist greatly in preventing hop matter etc from being transferred into the keg.

IMPORTANT: Before cold crashing, you must add pressure to the FermZilla. Positive pressure of approximately 10psi is required. before cold crashing. This is because as the beer gets chilled, CO2 in the headspace will be absorbed into solution. If there is not sufficient pressure (CO2) in the head space, this can cause negative pressure in the FermZilla which can cause the tank to be deformed once the atmospheric pressure is higher than the internal pressure.

Ideally, hooking the FermZilla to CO2 at around 10psi when cold crashing will prevent this, and also help to carbonate the beer before it is transferred.

To transfer the finished beer using pressure you will need a transfer line (a short length of line with a liquid disconnect on each end) and a Spunding Valve, as well as a purged, empty keg.

Pressure Transfer

Following the guide to Sanitising and Purging Kegs, you will have a sanitised, O2 free keg with a small amount of residual pressure in it.

1. Connect the FermZilla to a regulated source of CO2. Set the regulator to ~10psi

2. Turn the handle of the Spunding Valve clockwise (so that it does not let out pressure). Put the Spunding Valve on the Gas In Post of the sanitised keg

3. Adjust the Spunding Valve until it is venting at a pressure slightly lower than the pressure in the FermZilla (~7psi). Starting the transfer with a small pressure difference will help to minimise foaming issues

4. Connect the Liquid Post of the FermZilla to the Liquid Post of the keg using a transfer line (such as the Big Jumper)
5. The pressure differential will 'push' the finished beer into the keg

6. Once the transfer is under way, you can adjust the Spunding Valve down to about 5psi. The greater pressure differential will speed up the transfer process

7. Once the transfer is complete, disconnect the transfer line from both posts. Remove the Spunding Valve from the keg. Remove the gas line from the FermZilla

8. Congratulations! The finished beer is now kegged and ready to go. It should now be p[laced in a kegerator or similar ready for dispensing. If it was fermented and cold crashed under pressure then it will already be partially or completely carbonated. Connect the keg to CO2 at 10-12psi to complete carbonation if required

Pressure Transfer Setup | FermZilla

Closed Loop (Gravity) Transfer

Another method of pressure transferring the completed beer is a Closed Loop Gravity Transfer. This method is very useful if you wish to do a completely closed transfer (whereby no CO2 is vented during the process). This can be beneficial for super oppy beers as no hop aroma will be 'blown off' during the transfer process.

Another benefit of a closed transfer is that no additional CO2 is required - the residual pressure in the FermZIlla should be sufficient.

A Closed Loop transfer is effectively a siphon. Thus, the keg must be lower than the FermZilla for the transfer to complete.

Following the guide to Sanitising and Purging Kegs, you will have a sanitised, O2 free keg with a small amount of residual pressure in it.

1. Ensure that there is at least 5psi (ideally ~10psi) pressure in the FermZilla

2. Position the FermZilla and the keg so that the FermZilla is higher than the keg

3. Connect the Liquid Post of the FermZilla to the Liquid Post of the keg using a transfer line (such as the Big Jumper)
4. Provided there is less pressure in the keg than the FermZilla, beer will start to transfer. If beer does not begin to flow, pull the PRV of the keg to lower the pressure in the keg until the transfer begins

5. Once the transfer is underway, connect the Gas Post of the FermZilla to the Gas Post of the keg using a transfer line (such as the Big Jumper). This will keep the pressures equalised between the FermZilla and the keg, enabled the transfer to complete as a siphon
6. Once the transfer is complete, disconnect the transfer line from both liquid posts. Remove the gas line from the FermZilla and the keg

7. Congratulations! The finished beer is now kegged and ready to go. It should now be p[laced in a kegerator or similar ready for dispensing. If it was fermented and cold crashed under pressure then it will already be partially or completely carbonated. Connect the keg to CO2 at 10-12psi to complete carbonation if required

Closed Loop Transfer | FermZilla

NOTE: There are several ways to either stop the transfer automatically once the keg is full, or alternatively to monitor the process so that it is easy to determine when to stop the transfer.

A duotight Flow Stopper is an easy and inexpensive way to automatically stop the transfer. Simply place the Flow Stopper on the Gas Post of the target keg (you can use a longish length of line in order to add a Spunding Valve to this as well).

Using a Flow Stopper to fill kegs

A simple method is to place the keg on Digital Home Brew Scales before filling. TARE the weright to zero once everything is assembled, and stop filling at around 18.5kg - this will ensure the keg is filled below the gas dip tube.

If the beer has been cold crashed prior to transfer, then you can use the condensation line on the keg as a guide.

For a more precise guide for transferring cold crashed beer, a Cold Activated Keg Filler Sticker is a great way to help gauge fill volume during the transfer.