Guide on Closed-System Racking Methods

The “Gold Method”

Closed-system racking is the Holy Grail for meticulous brewers. Peter Wolfe highly recommends homebrewers try to create a closed-racking system, especially for hop-forward beers. The two closed-system racking options are most easily done with either a conical fermenter or carboys with a racking cane fixed into a hood cap, but it could also be rigged up with modifications to a bucket lid. There are two objectives to overcome to close your system off. The first goal is to purge the receiving vessel with carbon dioxide (or other inert gas). The second is to make sure you are adding CO2 into the top of the sending vessel.

The method is what we will call the gold method. First you slowly purge the receiving vessel (such as a Corny keg) with CO2 for about 1 minute on very low pressure (1 to 2 psi). Once the receiving vessel is purged, now it is time to rack. Using the carboy hood cap with a racking cane, push CO2 into the sending carboy, forcing the beer out of the carboy and into the purged receiving vessel (above).

The “Platinum Method”

Now for the platinum method. The first step in this method is to completely fill the receiving vessel with liquid such as a dilute iodophor or Star San solution. The second step is to push all the liquid out of the vessel with CO2. BYO’s Ashton Lewis adds, “This can be done in a carboy without adding any real pressure if the water is siphoned out of the carboy and displaced by very low pressure gas. We use this method at Springfield Brewing Company because purging was not working for us and we switched to water flooding about 10 years ago. It also uses less gas, but adds time to the schedule.” This method works incredibly comfortably and efficiently when performed on the BYO brewing system. We push the dilute sanitizing solution from one keg or carboy to another using CO2. Now we have a receiving vessel with 100 percent CO2.

Using a fermenter with a spigot at the bottom allows gravity to feed the beer from the fermenter to the keg or carboy, displacing the CO2 back from the receiving vessel back into the fermenter, making sure that no oxygen can enter the system. If for some reason you don’t have the luxury of gravity, pushing via your CO2 regulator works just as well. Just be sure to start very slow and low with CO2 if doing this, as you can over-pressurize the system very easily. Carboy caps and bucket lids were not meant to withstand pressure. Start with your regulator turned all the way to zero and very slowly dial up the pressure. Two psi is more than enough pressure to apply.

More from Big Book of Homebrewing

Excerpt from Big Book of Homebrewing, by Brew Your Own, published by Voyageur Press. Copyright © 2017 by Quarto Publishing Group USA Inc. All rights reserved.

Published on Aug 6, 2019


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