Carbonation and Head Retention
This is my first time using this forum. How exciting. I have been brewing a great IPA for seven years, and serving it at our brewpub, mostly on a beer engine at very low carbonation rates. We recently started to sell our beer wholesale, and I'm having problems with carbonation and head retention in kegs at other bars. My questions:
Should I invest in a carbonation tester to ensure that the kegs going out have enough CO2, or is there another way test for proper carbonation.
Could the head retention in the IPA be related to hop oils rather than carbonation levels? It is rather aggressively hopped both in the kettle and the conditioning tank.
Aggressive hopping should help head retention not hurt. If hopping is in the brew house and fermentation I would say hop oils should not hurt due to attaching to all kinds stuff (i.e. yeast) rather than to beer (did a quick search to verify this but could not find anything, so take it with a grain of salt).
You say you are pouring this beer through a beer engine at your establishment but did not specify whether you’re off site sales are through a beer engine.
If they are using beer engines off site then I can't suggest anything that could be different other than the obvious (beer clean glasses, clean beer lines etc.)
If pouring this beer through draft systems your typical beer engine carbonation is very low at roughly 1.4 - 1.8 vols co2. Cask ale head retention (and significant taste change) is primarily achieved through the entrainment of N2 into the liquid. If you push beer with co2 that low through a regular draft system you will have very flat lifeless beer (this would improve slightly the longer the beer sits tapped gaining CO2). Typical draft beer is around 2.5 vols.
If you are trying to produce beer for off site sales on typical draft systems then I would say that a carbonation tester is essential to ensure consistency and pourability of your product. Zahm & Nagel is the most common (read least expensive) supplier of these units.
Last edited by Tbrew; 01-04-2005 at 01:12 PM.
Carbonation & IPA
Hi dyoung & Tbrew,
We has been producing and selling IPA wholeslae for more than 10 years out of our small 7 Bbl Brewhouse and if I may, I would like to note a few observations in response to your questions. We have dry hopped opur brew the whole time, and do not own a Zahm unit to test carbonation levels (yet).
From what I am reading in your note, your carbonation levels are too low and producing the lack of head retention you are seeing in outside accounts.
There are a few things that will ADD to head retention:
1.) Proper carbonation levels.
2.) Dry Hopping.
3.) USe fo Crystal or Dextrine Malts.
4.) Infusion mashing as opposed to step mashing.
5.) Do not filter.
6.) Entrained Nitrogen gas.
7.) Cask conditioning.
As Tbrew had mentioned, dry hopping would only help to create a nice head on your pint. Depending on your carbonation process, there are a couple of procedures you could use.
One is to force carbonate in the keg, as we do here at DK. Regrigerate your 1/2 Bbl keg to 36 F (in a walk-in) and attach a keg coupler to force CO2 into the keg at 34 - 36 psi for 48 hours. Leave about 1" headspace in the keg and do not vent off excess pressure at the end of 48 hours. Just remove the coupler and cap. We have done this for 10 years, but you have to be dilligent about getting the kegs off the CO2 at the end of 48 hours or they're overcarb'd.
Another method is to carbonate in a conditioning tank, as most Breweries do. When you load your beer to the tank, set your carbonation stone pressure to 12 psi and give it a day or so at a cold temp to stabilize and counterpressure fill. There are probably excellent write-ups on this subject in the discussion group and you can look them up there.
Infusing a bit of Nitrogen gas can also produce an elegant head on a pint since the Nitrogen will not pass through the bubble membrane as CO2 does. However, this will not produce a "live" beer since you still need carbonation to give it that sparkle. The Nitro will come out of suspension upon pouring from the tap, as it does in a Guiness pint (also, Guiness has a much higher concentration of Nitro that you would need / desire).
The drawback to this is that you still need to add CO2 and add the Nitro in some sort of procedure that is a snick above and beyond your typical carbonation schedule.
Cask conditioning is great for in-house sales but I would caution against it for the reasons you are seeing now. It's a bit "hit and miss" for me and requires quite a bit of experience and practice to get perfected for outside sales.