Despite some fancier primary fermentors with spigots (Ss Brew Bucket and Speidel), my post-fermentation-transfer game is basic. I do most of my racking via gravity and auto-siphon. It gives me control, and I haven’t had issues with oxidation on NEIPAs and other oxygen-sensitive styles as long as I purge the keg. Open transfers aren't really an option for carbonated beer though.
I wanted to combine Brett fermentation under-pressure and dry hopping. I did the first dose in primary to allow time for bioflavoring, but I wanted the Brett to have time to work before the final dose of hops to create developed Brett and fresh hops aromatics. My solution was to naturally keg-condition for six weeks and then jump the carbonated beer to a purged serving keg containing bagged and weighted hops.
When transfering carbonated beer between kegs, the goal is to have slightly more pressure on the filled keg than the receiving keg so that the beer is gently pushed from one keg to the other without the beer foaming. This is essentially the same method as counter-pressure filling a growler or bottle only on a larger scale.
Step 1: Purge and then pressurize the receiving keg to the same pressure as the filled and chilled keg (15 PSI in this case).
Step 2: Connect the filled keg to a tap and dump the first pint to remove most of the sediment.
Step 3: Connect the two kegs from out-to-out post via a jumper line (a short length of tubing connecting two liquid quick disconnects).
Step 4: Connect the gas line to the filled keg to and increase the pressure slightly (17 PSI in this case).
Step 5: Connect a spunding valve to the receiving keg and set it to the same pressure as you pressurized the keg earlier (15 PSI).
Step 6: Wait for the transfer to complete (approximately five minutes).
Step 7: Disconnect the jumper line, gas line, and spunding valve.
Step 8: Connect the serving keg to the gas and serving line and enjoy reduced sediment beer!
This is also a great technique if you travel with kegs and want sediment free beer so yeast isn’t knocked into suspension during transit.
Smell – Varied aromatics of herbal lemongrass, apples, and pepper. Brett is subtle, behind the hops. Hops aren’t grassy or vegetal despite extended contact with the pellets in the keg.
Appearance – Slight haze, but overall it is a bright beer. Yellow gold. The white head is thick, but drops after a few minutes.
Taste – Similar to the nose with bright-integrated citrus notes on a peppery saison backdrop. The finish has a hint of earthy Brettiness. Deceptively complex because it is easy to drink. Mellow hop bitterness. Slight perceived sweetness thanks to the citrus character and slightly higher than expected final gravity.
Mouthfeel – Thin and crisp without harshness and tannic bite. Carbonation is a little low for a saison.
Drinkability & Notes – Crushable hoppy saison, has been a perfect beer to have on tap for summer. The hops cut through the Brett and everything works together.
Held up well in the keg so far (kicked the next day), which I assume means I didn’t introduce much oxygen when I jumped it over.
Changes for Next Time – Not much to change for this, although I'd lower the mash temperature if I was planning on the same timeline again. Could have given it another couple of months in the keg to condition before going onto the keg hops for a little more Brett character.
Batch Size: 5.75 gal
Final pH: 4.35
Brewhouse Efficiency: 78%
Boil Time: 90 Mins
65.0% - 6.5 lbs Dingemans Pilsen
25.0 % - 2.5 lbs Flaked Wheat
7.5 % - .75 lbs Dingemans Cara 8
2.5 % - .25 lbs Weyermann Acidulated
Mash In - 45 min @ 154F
1.00 oz Saaz (Pellet, 2.75% AA) @ 10 min
1.50 oz Azacca (Pellet, 15.00% AA) @ Whirlpool 15 min
2.00 oz Azacca (Pellet, 15.00% AA) @ Brew Day Dry Hop
3.00 oz Azacca (Pellet, 15.00% AA) @ Keg Hop
5.50 g Calcium Chloride
OYL-217 Omega C2C American Farmhouse
4/22/17 Brewed by Audrey
No sparge. Mash pH measured at 5.24. Collected 7 gallons of 1.039 runnings. A bit lower gravity than expected, extended boil to 90 minutes.
Chilled to 69F. No starter, pack less than a month old. 2 oz of brew day Azacca.
Left at 70F to ferment. Warmed up to nearly 80 for days 4-7. Then the weather cooled off.
5/6/17 Kegged with 3.75 oz of table sugar and was left to condition (no extra dry hops yet). A bit less attenuation than expected.
6/13/17 Moved the keg to the fridge.
6/16/17 Jumped to a freshly purged keg with more Azacca weighted with marbles and bagged in a knee high.
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I'm not sure I understand why you need/want counter pressure when transferring carbonated beer; can't you simply purge Keg 1, put it on serving pressure, transfer to Keg 2 with a gas disconnect, then pressure it back to 15 PSI?ReplyDelete
Thanks for your work! Cheers!
Have considered (or used) Cask Widge Floats (https://www.craftbrewer.com.au/shop/details.asp?PID=4382) in your kegs? I have one set up currently so I can keg hop without a hop bag and serve sediment free.ReplyDelete
Theoretically this would allow you to ferment (with a spunding valve), brett condition and dry hop all from the same keg, significantly reducing oxygen exposure. As far as I can tell, the biggest risk of oxidation is putting the spunding valve in the keg if you didn't have it installed during the primary fermentation.
Counter-pressure is gentle (no foaming, no loss of CO2) and easy. I'm not sure exactly what you are purposing from your description. Keg 1 has the beer, why are you purging it? Pushing through the gas side means the beer is falling down into the bottom of the keg and splashing.ReplyDelete
I haven't, I usually don't have issues with sediment after the first pint. I'd rather not leave the beer on the primary trub during serving. It also wouldn't help this system (dry hopping carbonated beer is a great way to end up with a beer-geyser)! Wouldn't hurt to have that in the keg you were transferring out of.
What ph meter do you use? Also, if you didn't sparge did you just mash super thin with a lot more water than normal? Do you mash out? What is your final running gravity into kettle w this method? Cheers!ReplyDelete
I have a Hanna Halo and a Milwaukee MW102. The Halo can take readings directly in the mash tun which is convenient, but it is pricey (twice as expensive, no replacement probes) and requires a Bluetooth connection to your phone.ReplyDelete
Not that much more water than usual, I usually only sparge with ~15% of my total water. With no sparge your first runnings and final runnings would be identical. No mash out. Here's the write up on my usual process, Minimal Sparge.
Mike - There is a way to transfer under pressure that I find to be slightly better in that there is no risk of pushing beer into the spunding valve. I can in no way take credit for this idea. Essentially, one connects the two gas in lines to the CO2 source via a tee mannifold. Then, the two beer out posts are connected via a single line. The receiving keg is placed lower than the delivering keg. The purged, receiving keg is vented very briefly to start the siphon. The beauty of this method is that one can walk away from it without any wory of beer overflowing the gas connection where you currently have a spunding valve. I first read about this on Braukaiser's blog here: http://braukaiser.com/blog/blog/2012/08/13/five-things-that-made-brewing-easier-for-me/ReplyDelete
Sorry, I wasn't clear it seems. What I was suggesting was to simply depressurize the first keg, and push the beer in the second keg at serving speed, liquid post to liquid post, naturally. The second keg would be purged first with CO2, but the gas post would be simply left open. How is that different to using a spunding valve? Cheers!ReplyDelete
Thanks Rob. Certainly seems like a nice option, although sounds like more setup required (I can just use my lines in their serving configuration for this). No issue with the beer getting into the spunding valve thanks to the pressure and slow transfer, this time anyway.ReplyDelete
Michaël, ah got it! Anytime you transfer into an unpressurized vessel (bottle, growler, or keg) some of the CO2 will come out of solution. That can be increased by shorter lines, warmer keg, nucleation sites etc. and cause foaming. Luckily with kegging you can just replace that carbonation easily, but the foaming could be a mess if it starting coming out of the gas post.
I ferment in kegs, and this type of transfer is one of the primary reasons why. It's super simple, and there's virtually no risk of introducing oxygen during the transfer.ReplyDelete
If you want to further minimize oxygen exposure, you can fill the receiving keg full of sanitizing solution such as Star-San or iodophor, purge the minimal remaining headspace several times, then push the sanitizer out with CO2. Purging is never 100% effective at removing all air, so the less headspace you start with the better.
Hey mike, hope your well.ReplyDelete
You mentioned the combination of brett anddryhops under pressure.
canyou talk me through your process?
Anything in particular? The timing is down in the notes at the bottom of the recipe, and the specifics on jumping keg-to-keg are in the post itself.ReplyDelete