Tag Archives: kegging

Repurposing and Conserving CO2 During Kegging

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With the current recommendations and restrictions on leaving the house, I’m trying to conserve basic brewing necessities as much as possible. This includes propane and CO2–neither of which can be ordered online (and really don’t count as necessities in the same way that groceries do, so it’s hard to justify many extra trips out to get more).

Keg purging is one brewing task that’s non-essential but nice, in terms of long-term beer quality. By keg purging, I mean replacing the ambient atmosphere in a keg (the stuff we breathe) with CO2 from a tank, to greatly reduce oxygen concentrations and postpone noticeable oxidation in the beer. My usual procedure prior to kegging is to fill a keg with StarSan, and push it out using CO2 from my CO2 tank. This doesn’t use a ton of CO2, but it still does use some up that could go to other purposes.

The easiest CO2-conserving scenario is to go without a keg purge, which is my normal procedure anyhow for many “non-delicate” beers (e.g., porters and stouts). However, I’ve noted that lighter lagers, pilsners, and blonde ales do show noticeable oxidation effects within a month or two without a keg purge. In the “good old days” of sharing growlers and homebrew happy hours and such, I could finish a keg in 4 weeks or so. Now, I expect many kegs will stay on service longer, and so I want to extend the quality as much as I can. Keg purging is nice, if possible!

One option I’ve considered is to use sugar-based carbonation (wort-driven krausening or corn sugar), which should both eat up any latent oxygen and carbonate simultaneously. I’ll likely try that for some future beers (especially more robust, darker styles), but I worry about oxidation risk from adding the sugar and also leaving the beer at slightly higher temperatures to allow the yeast to carbonate more quickly. It’s not an ideal option for light lagers.

So, how might I purge kegs to avoid oxidation and simultaneously conserve precious CO2 from my tanks? Reuse CO2 from empty kegs!

When a keg in the keezer is drained of beer, it’s full of CO2 at serving pressure. Normally, I just bleed this off before cleaning the keg. Why not repurpose the gas?

So, I hooked up a jumper between the gas ports of the empty keg and a StarSan-filled keg (the latter being the one I’ll fill with fresh, uncarbonated beer). Before doing this, I let the empty keg warm up, to give a bit more gas volume (yay, physics). I put a picnic tap on the StarSan-filled keg, hooked up the gas, and let the empty keg push out the StarSan.

It worked like a charm! The transfer took around 10 minutes, but the whole keg got drained, with a bit of residual CO2 left over. No CO2 went to waste, and I ended up with a purged keg ready to fill with pilsner!

The keg setup for CO2 purge. The keg at lower right is empty and just moved out of the keezer. The keg at upper left is empty and filled with StarSan. The red line is pushing CO2, and the clearish-white line is moving the StarSan into a sanitation tub (for use sanitizing equipment).
The colored lines and arrows here show the path of the gas and liquid. The yellow arrows indicate the flow of CO2, and the red arrows indicate flow of the StarSan.

Beer Update: Palaeotis Pils & Gondwana Pale Ale

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Gondwana Pale Ale 1.5

I kegged the latest iteration of my Gondwana Pale Ale on 7 June 2017, adding two ounces of dry hops in a baggie at that time. Final gravity was 1.012, down from 1.053, for 5.4% abv.

Initial tastings show that this should be a pretty decent beer. It has a bit to mature yet, in that the yeast haven’t totally settled out and that seems to impart a harshness to the bitterness. I expect this should be much improved by the time I get back from Homebrew Con.

20170611_131001Palaeotis Pils 1.1

After brewing this beer on 20 May 2017, I started it at 50° and then let it ferment at 54° after a few days. I raised the temperature to 64° on 1 June, and then cold-crashed to 33° on 7 June 2017.

I kegged this beer today (11 June 2017). It has a final gravity of 1.011, down from 1.048, for 4.7% abv. At the time of kegging, I also added 1 tsp. of gelatin dissolved in 3/4 cup of water and heated to 152°, as a fining agent.

This beer tastes and smells amazing–I anticipate that it’s going to be a fine brew once it is clear and carbonated! Everything is on-point, and it’s a nice change after the disappointment on my Bohemian pilsner.

Big Batch Update: Saison, Amber Ale, Pilsner

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There’s lots to report with kegging and fermentation for a few recent batches. So, here’s what’s new:

  • Thumbspike Saison 2.0
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    • This might have had the quickest turn-around on any kegged beer I’ve ever done! I brewed the beer on 12 May 2017, starting with an 80° fermentation temperature. On 16 May, I raised the temperature to 85°. Everything really churned along, from start to finish (as you might expect with fermentation at those temperatures)! I kegged the beer on 20 May 2017, with a final gravity of 1.004. That works out to 6.7% abv. I’ve had it on tap for about a week, and it’s a pretty interesting and enjoyable beer. All of the ingredients melded together quite nicely, and I am pleased with the results. It’s a very refreshing brew for a warm afternoon on the patio.
    • My first impressions are that it has a very lightly fruity aroma, with a slight tartness on the flavor. Head retention seems pretty miserable at this point, but I don’t know if that’s a real feature of the beer or because I didn’t wash my glass from a previous beer before pouring this one.
  • Hell Creek Amber Ale 1.1
    • I brewed this beer on 14 April 2017, with a starting gravity of 1.060. I kegged the beer on 7 May 2017. Final gravity was 1.016, which equates to 5.8% abv.
  • Czech-ed Out Pilsner
    • This batch has the honor of being my first dumper, ever. I’ve weathered warm fermentations, low gravities, and incomplete fermentations, and have always soldiered through in the end. Alas, this particular batch just wasn’t any good. The culprit wasn’t infection, bad fermentation, or anything like that. It was bad hops! As noted in my original post, the late hop addition smelled really grassy. I should have known better than to add them to the kettle, but wasn’t quite that smart. So, I kegged the beer, carbonated it, and pulled my first sample…to a whiff of pilsner that smelled pretty much like freshly mown lawn, and not in a good way. It was almost reminiscent of jalapenos, but in any case was not reminiscent of what a good European pilsner should taste or smell like. Lesson learned!
    • In terms of fermentation history, I started fermentation at 50° on 9 April. I raised the beer to 65° on 21 April, and then dropped it to 33° on 30 April 2017. I kegged the beer on 14 May, at which point it had a final gravity of 1.011. This equates to 5.6% abv.

Update: Dunkel-Osteus, Raspberry Belgian

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Raspberry Belgian Ale sample

During the past week, I kegged both my Munich Dunkel (“Dunkel-Osteus“) as well as my raspberry Belgian ale. Let’s take a look at the details since brew day for each.

Dunkel-Osteus

This pun-fully named beer in the Munich Dunkel style fermented at 54° for 17 days, before it was raised to 68° on February 28. On March 6, I cold crashed it to 33°, and let it sit for an additional 16 days before kegging on March 22. At this point, the final gravity was 1.016, for an abv of 4.5%. I set to carbonating immediately–the sample I pulled a few days later is really, really tasty. I’m liking this beer so far, and it should be pretty exceptional once it has conditioned for another week or two.

Raspberry Belgian

I brewed this beer on March 10, and added the raspberry puree on March 14. To make the puree, I added about 1 cup of vodka and 18 oz of frozen raspberries to a blender. Then, I blended them until they were nice and pureed, before tossing them into the fermenter. I figured the vodka (which I ran first) would kill anything nasty in the blender (or anything remaining on the berries). I let this mixture ferment for another 12 days; by this point, the raspberry seeds, etc., had dropped to the bottom and the beer had cleared pretty nicely.

I kegged the brew on March 26. Final gravity was 1.011, down from 1.039. This works out to an abv of 3.8%. The beer has a nice pale pink color and a beautiful raspberry aroma. The raspberries come through nicely on the flavor, too, although the beer as a whole could use a bit more tartness and body. I’ll see if that perception remains accurate after carbonation. I was tempted to throw in some lactic acid, but figured it would be best to carbonate first and test if that helps.

Holy Helles & First Amendment Blonde Ale Kegged

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I did a whole mess of kegging tonight, to clear out fermenter space and move along some projects.

First up was my Holy Helles (a Munich Helles), which I split into two 2.5 gallon kegs. The reason behind this was that I plan to enter it in the National Homebrew Competition, and also to serve it at Easter. I didn’t want to dose the Easter beer with gelatin (in case some of our guests don’t do gelatin), but don’t much care for the NHC one.

A few notes on the helles fermentation…on 21 January 2017, the gravity was down to 1.014. At this point, I raised the temperature from 50° to 68° for a diacetyl rest. I left it at this temperature for about a week, and then dropped it down to 34° until kegging.

Final gravity was 1.012, a touch higher than predicted (1.010). With a starting gravity of 1.047, this equals 4.6% abv. That should make a nice, drinkable beer!

Next, I kegged the First Amendment Blonde Ale. Final gravity was 1.011, down from a starting gravity 1.051, for 5.2% abv. I hit my numbers perfectly on this batch–wow, what a nice treat!

I’m storing these beers at 34°, and force carbonating the blonde ale right away.