I’m a huge fan of sanke kegs. I use them not only for serving my beer, but also for fermenting my beer. A couple months back I detailed my intended set up for fermenting and kegging with sankes -- now, after a couple ferments there have been some minor changes, and I must say overall it’s been working quite well! This is a companion post to that first post on the subject that talks about how this all works in actuality.
I’m now making use of a 2″ tri clamp (TC) blow off tube from NorCal Brewing Solutions (found here). Works great for the most vigorous of ferments. The fermentation chamber is just a full sized all-fridge, with a heavy duty platform to handle the weight of full fermentors.
When I go to cold crash the finished beer I will replace the blow off tube set up with a TC CO2 connection. With this I will keep a slight CO2 pressure on the beer while cold crashing so that no “suck back” (of either liquid from the blow off flask, or oxygen from the air) occurs as the gases in the headspace of the fermentor cool and compress.
Initially I was planning on using a full TC racking set up, but I am now using a simple 1/2″ NPT tee that is welded to a 2″ TC cap (also from Norcal Brewing Solutions, link) with a CO2 connection on one side, and a bored through 1/2″ compression fitting for the racking tube on the top (from Brewer’s Hardware, link). There were a couple reasons for this. One of the main ones was that the TC set up added too much height, and limited the depth I could lower the stainless racking tube to. Plus, there are no 1/2″ compression fitting -- TC adapters available that I know about, so I was already going to be playing with threaded fittings, and this simplified things nicely.
With a slight CO2 pressure, I purge the headspace of the fermenting keg and the transfer line and fittings. I then lower the adjustable racking tube into the beer. The beer travels through the racking tube, over towards the serving keg (which has been sanitized and purged with CO2 as well). If CO2 bubbles appear, I know I must lower the racking tube. To ensure no sediment makes it into the serving kegs, I keep the racking tube rather high -- within a couple inches of the surface of the beer in the fermentor by my estimation. This has worked perfectly -- and the beer is very clear.
The sanke filling head remains unchanged from my earlier post, and works quite great too. It has a butterfly valve so I can quickly stop the transfer if I need to switch to a second keg, or if sediment appears in the sight glass. Probably a bit overkill, but sightglasses make the most mundane brewery tasks entertaining, so there’s that.
Here’s what the process looks like -- this video shows what happens with the racking tube is too high and needs to be adjusted downwards. I have a good idea of the transfer speed at this point and typically don’t let this happen, but it’s not a big deal if it does!
If you have any questions about fermenting in sanke kegs and racking out of them, let me know and I will try to help.