How to Fill Sanke Kegs Directly from a Fermenter

March 18, 2020

The BREWHA 4-in-1 conical fermentors (mash, boil, ferment and carbonate) enable you to save money and serve the best beer by minimizing transfers that take time and can contaminate your beer in the process. Once fermentation is complete, if fermentation gas was not captured, the beer can be force carbonated from the top of the tank. Carbonation stones can be used from the bottom, but they don't increase the speed substantially, can scrub some aroma compounds from the beer, and they stir up yeast that may be settled on the sides so we recommend against them. By lowering the temperature of the beer by using one of our Water Chillers, the beer can be fully force carbonated in the fermenter in about 3-5 days (brewers will often close the blow-off valve late in fermentation and with a pressure guage to monitor, allow the pressure to rise naturally to ~14psi through capturing the CO₂ from fermentation; at 19C/66F at 14psi there are about 1.7 volumes of CO₂ and the remaining gas volume will be added while crashing to ~6C/43F over 48-72 hours). Since carbonation occurs much slower at higher temperature and one can't put as much CO₂ into the beer (CO₂ dissolves much less readily at higher temperature), a temperature of about 6C/43F is recommended with 12psi of CO₂ (setting your gas regulator to 12psi will ensure you don't waste gas out the fermenter pressure relief valve; check the functionality of the pressure relief regularly) for most beer styles (this delivers about 2.3 volumes of CO₂).

Once the kegs are cleaned and sanitized (see this link on cleaning/sanitizing kegs with the BREWHA Manual Keg Washer) they can be filled (a process called transferring, kegging or 'racking') following these steps:

STEP 1 Clean and sanitize the Keg Racking Hose (this was discussed in the Keg Cleaning article mentioned above) and ensure that the racking port on the fermenter is clean/sanitized. Sticking a pot of boiling water over the fermenter racking valve for two minutes can heat sanitize the valve, and then spray the valve out with Star San or other sanitizer.
	STEP 2 Close both shutoffs (liquid and gas) on the coupler and connect the Fermenter to Keg Racking Hose to the fermenter. Then open the fermenter valve, and temporarily open the liquid shutoff on the coupler to empty about 0.5L/quart into a pot to flush yeast/sediment out of the racking arm. (To send liquid 'backward' through the coupler, the check valve/ball needs to be removed. See the image near the bottom of the page at this link.)
STEP 3 Connect the coupler to a sanitized keg ready to be filled.
	STEP 4 Ensure that CO₂ is connected to the 4-in-1 fermenter to maintain pressure in the fermenter (about 12psi is recommended). Then open the liquid shut off valve on the coupler and start filling the keg. The gas release valve on the coupler will need to be cracked to allow CO₂ to escape, otherwise the keg will not fill all the way. Don't open it fully and empty all the gas, or the beer will start to foam inside the keg and make filling more difficult and carbonation will be lost. It is best to control the beer filling speed by partially closing the gas release shutoff on the coupler (beer should be able to enter slightly faster than gas can escape so that the pressure of 12psi is maintained in the keg).
STEP 5 The keg should be filled on a commercial scale and filled about 98% full, or leaned against something solid while filling, so that there is a pocket of gas at the top of the keg that won't fill with beer (as the keg fills, gas will be trapped in the space above the neck of the spear). This ensures that there is a small amount of space that remains in the keg that can absorb pressure changes. If a keg is filled right to the brim, and the beer warms up, pressure will rise rapidly in the keg, and very likely the keg will leak beer. (Gas compresses much more than liquid, so with the gas space in the keg, pressure won't change very much when the keg experiences some temperature fluctuation.)
	STEP 6 When the keg is full (as shown on the scale, or if tilting the keg, beer starts to spray out the partially closed gas shutoff valve) close the gas shutoff valve on the coupler and wait until beer flow stops (to bring to 12psi in the kegs), close the liquid shutoff valve on the coupler, and disconnect the coupler from the keg and move to the next keg. Once the kegs are filled, they can be topped up with CO₂ (same method as discussed for purging the kegs in Step 11 of this article) but if the beer is cold and pressure was maintained in the keg when filling (about 12psi) there shouldn't be any need.
STEP 7 The keg spear should be rinsed off with water to remove residual beer (that microbes would love to grow in!) and then spray sanitized (with Star San or similar sanitizer).
	STEP 8 The keg can be capped for storage (standard 2" TC caps work pretty well or keg caps can be purchased from keg suppliers).

And that's it—beer is ready to be served (once conditioning is complete)!

Note on serving: remember when serving from kegs (with either the Lindr Kontakt Beer Chiller Dispensers or any standard draft system) the gas into kegs should be always at the keg pressure, or foaming in the serving lines will occur as gas comes out of suspension.

Learn: How to transfer beer from a fermentor to a Cornelius (soda) keg