These are the instructions I am following for my first closed transfer: Here’s how you complete this entire process in a few easy steps. First, when you clean your keg, also clean your transfer line and anything else that has direct contact with your beer – choose your favorite cleaner (PBW, Oxi-clean, etc.). Then sanitize with a no-rinse sanitizer, my go-to is Star San, which can be mixed up in one gallon batches using 6.1g of Star San. This is enough to completely sanitize the inside of your keg with little waste, making sure to rotate the keg so it coats every surface. Empty the sanitizer from the keg by hooking up your CO2 tank, pushing the sanitizer from the out post of the keg through your transfer line thus sanitizing it in the process. Disconnect the transfer line so you can burp the keg, pressurize it to 5 psi, shut off the gas, and then vent it through the keg lid. The CO2 is heavier than air, so as you add it to the keg it will sink to the bottom, pushing air out through the top. How To Do A Closed Transfer With the keg full of CO2, it’s now time to connect the hoses. Make sure to sanitize the spigot as normal and connect your liquid tubing, then connect the liquid disconnect to the “out” post on the keg. Pull the airlock or blow-off tube out and spray the end of the gas tubing with sanitizer before inserting into the lid, connecting the gas disconnect to the keg. With the fermenter higher than the keg, you can now open the valve and watch the beer flow into your keg, displacing the CO2 into the headspace and completely eliminating any oxygen from contaminating your fresh beer. The best part about this setup, is that it’s a cheap option for closed-loop transfers, especially considering gravity is free. Here are my questions: "Disconnect the transfer line so you can burp the keg, pressurize it to 5 psi, shut off the gas, and then vent it through the keg lid." (from above) 1. I disconnect the transfer line and burp the keg. Is this simply using the pressure release valve to release the pressure in the keg? 2. I then pressurize the keg to 5 psi and shut off the gas. Then I remove the keg lid to vent it? Does that make sense? Won't the oxygen start mixing right away with the CO2? Or does the author mean pressurize it to 5 psi, then use the pressure release valve to vent the keg and remove the oxygen which should be at the top of the keg since CO2 is heavier than oxygen and will push the oxygen to the top and subsequently out the pressure release valve. If this is the case, probably a good idea to do it a few times, right?
Yes. Nope. Yep. You'll want to do several pressurize/purge cycles, all with the lid on. And you'll want to use much higher pressure than 5 PSI. When you pressurize the keg with CO2, the CO2 does not sink to the bottom. It mixes fully with the air inside. So each purge/release cycle reduces the amount of oxygen in the keg to a level lower than the previous cycle. Here's a presentation you might find helpful: http://sonsofalchemy.org/wp-content/uploads/2021/09/ClosedTransfers.pdf ETA: If you plan to use a gravity loop as suggested in the instructions you copied, you'll want the keg to be at a relatively low pressure at that stage, not at the higher pressurize/purge cycle pressure.
After looking at your link to that presentation, I like the idea of just filling the keg with StarSan solution and then purging it. Guaranteed to get all the oxygen purged. Thanks again!!
From my reading it appears the keg should basically be at zero pressure for the gravity transfer? If there is zero pressure in the keg, as the CO2 leaves the keg and goes to the fermenter, the liquid from the fermenter is filling the keg, so the pressure should remain the same, correct? Or will a tiny bit of pressure in the keg be needed? If so, how much? Would 5 psi blow the lid off my plastic bucket fermenter?
You can start the transfer at basically 0 PSIG in the keg, as long as the fermenter has been pressurized. It's the differential that will get the the beer flowing. This guy shows/explains it pretty well: ETA: I don't know what pressure your bucket lid can handle. You might want to start very low, i.e. just enough to move beer.
Yea, no. You have o2 in your co2, and o2 in any sanitizer left in the keg. But this method is probably your cheapest and easiest method for the 80/20 rule.
In your "Generic Closed Transfer Chain" slide what is the need for attaching the spunding valve to the keg? I've been using a gas QD with tubing stuck in a jar of water which gives about 1 psi. Stick it a little deeper if more pressure is needed.
The spunding valve lets CO2 out and nothing in. In my case, I'm taking the spunding valve that was already on the fermenter and putting it on the keg, so it's easy.
For transfer pressure relief, it's probably just as good. But for fermentation, water doesn't stop O2 from getting in. It just slows the rate of ingress. It's probably not a real problem while lots of CO2 is being produced and blowing out. But once that settles down, a spunding valve is IMO better, because when it's closed, it's closed.
