Saturday, October 6, 2012

That 'Keg Beer' Flavor

As much as I have come to rely on kegs for serving and storing my beer, for I really dislike the inconvenience of bottling, it has become increasingly apparent that force carbonating every beer style is not ideal. And considering that the vast majority of beers I brew are English inspired and designed to showcase some of the flavors you'd find in UK cask ales, it is rather ironic that I serve my beers from the very thing that is the direct opposite of 'cask conditioned.' One common issue I have had with brewing English style beers, is that oftentimes the flavor of the beer out of the fermenter is richer tasting and has more *yeast* character than the same beer that has been sitting in a keg for a few weeks. I would like to find a way to preserve the yeast character of a beer, as it tastes out of the fermenter, while still allowing the other flavors to develop as it sits in the keg. Is this even possible? Preserving the initial yeast character while still allowing the beer's flavor to mature? 

Ok, so what would be the best way to achieve this, should it be possible - Bottling? Keg? Cask? Foremost, I still believe that force carbonating is superior to bottling, at least for the beer styles I am interested in. The beauty of kegging is that it allows you to take a beer out of the fermenter and serve it in a week or two's time, without worrying if the yeast will reactivate in the bottle and produce off-flavors, or over carbonate. Also, without adding priming sugar, there is little chance the beer's flavor will change during the secondary fermentation. This I am certain of. And with kegging, I do not believe in a rushed method of carbonation. Shaking your kegs to get faster C02 absorption is just as bad for the beer as setting the regulator at 30psi and letting it rip. I have had my best results kegging English style beers by setting the regulator to 10psi and letting it sit for a few weeks in the kegerator before dropping the psi to 3-4 for serving. I also have found that crash cooling the beer to 40-45F after the bulk of fermentation has finished helps retain more yeast flavor than letting it sit in the primary for weeks on end. 

From my experiences and what other people have indicated, I can assume that the loss of yeast character from kegging either due to the yeast continuing to cleaning up after fermentation has finished, or that the process of force carbonating does something to change the flavor of the beer; as if that the combination of cold temperature and high pressure (via forced C02) "scrubs out" some of the flavor. Aside, I have also noticed that it typically takes two-three weeks after kegging for the flavor profile of my beers to come around. Going into the keg they taste great, but once in the keg and under pressure they get hazy and sort of 'twangy,' before clearing up and tasting great. Similarly the same can be said for hop character. Often times I've noticed the hop character and flavor of my beers to be temporarily diminished while the beer is carbonating, before everything is back to normal a week or two later.

when bottled beer goes bad
While serving all of my English beer from casks would probably be the best thing to fix this yeast flavor issue - as the slow and temperature stable process of cask conditioning is certainty more conducive to maintaining a beers flavor than kegging - such a thing isn't feasible for me at the moment. Not only do I not own a proper cask set up (yet), but I'd have problems finishing a cask without a receptive group of friends, of whom currently  "don't like" cask ale. Until this changes, I'll have to stick with my kegging set up. Also, while kegging may not be the best or most authentic method of serving English style beer, I feel it is still better than bottling alone and results in a more consistent beer. I can't complain. Lastly, here are a few ideas I have mulled over for simulating a cask serving method, as to preserve that 'yeast character' I so like.

Conduct the whole fermentation, start to finish, in a keg that has a shortened liquid-out tube. Three quarters of the way through the fermentation the lid is sealed and the keg is lightly pressurized. This way, the beer is naturally carbonated and the beer can be served directly from the keg and topped up with c02 as necessary. If beer right out the fermenter tastes best, why not serve it from it? I suspect this may work, but I'm hesitant to try. Also, would it might be worthwhile to carbonate the beer via priming sugar in the keg and then serve it via gravity on it's side. Or a cubitaner with a spigot might even work, if you can drink it fast enough before it oxidizes.

Eh, probably just easier to spend the cash and buy a proper cask and handpump. One day...


  1. if you do get a cask, i find with mine they keep well with a cask breather. If temperture is a problem, then you can use a probe through the shive attached to a beer chiller unit (on a thermostat if necessary). I've heard of some folk using a bucket of water in a fridge, hooked up to a small pump if you don't have the beer chiller. works well and you get the cask experience without having to drink the beer quickly. I made my first 'cask probe' from beer line (which worked well - and cheap!). Also found the beer matures much more quickly in cask than bottles - although you may already find that with your kegged beers? Hooked up to a beer engine you can strike just the right balance in terms of condition in the beer and it is very satisfying to get the 'cellering' bit right. Go on get a cask ... i know you want to ;-)

    Ben (fuggledog)

  2. I agree that getting a cask setup is probably the best option, and something I've been considering myself. Btu the expense of it (handpump, yet another fridge/freezer, another CO2 bottle and regulator for the cask breather, etc.) has delayed me from pulling the trigger. So on to the other options.

    I'd be a bit worried with doing your idea of fermenting in a corny and serving from it. The trub probably won't cause problems for the month or so the beer is on tap, but I still wouldn't like it sitting in there. If the keg is bumped or moved you'll be serving murky beer until it settles again. Something that may work instead is to transfer your beer to a keg and seal it up once fermentation starts to wind down, much like they do with cask ales. The timing might be a little tricky, but I don't think it would hurt things if it was done a little early or late. Just let the beer finish out in the keg, then move it to the kegerator and serve. One of the problems I see with that method, though, is that I already have a hard enough time getting these british yeasts to attenuate to the level I would like. By moving it off the bulk of the yeast slightly before it is done, fermentations could stall and attenuation could be lower than desired. I would still prefer to do it this way as opposed to adding corn sugar to a keg of finished beer to let it prime that way. As you're well aware, the addition of corn sugar to a finished beer brewed with and english yeast (especially Fullers), causes some inexplicable degradation of flavor. I think allowing the beer to finish fermenting in the keg to produce a low level of carbonation would be much preferable.

  3. What if you transferred to the corny once fermentation is almost complete. Lay corny on its side using braces on each side so it doesn't roll. You can previously modify the dip tube so it bends to the side wall(towards the top of the keg when on its side) so you can apply CO2 to adjust final carb. Then you can dispense it with gravity from the gas out poppet. You can either let a little air in and let it stale/mature a bit in CAMRA style or apply a really low shot of CO2 at the end of a session or when the vacuum prevents pouring, to blanket the beer.

    With the keg on its side it will give a nice long surface for the yeast to collect and may have more of a cask flavor effect. Just thinking out loud.

  4. I put a U bend in my corny keg dip tube ,
    Dump the finished beer into a CO2 flooded Keg with 25g of boiled priming sugar and seal at 0 psi and keep at 21 degrees for 1 week to 10 days, until the psi stops rising.
    Crash cool for 2-3 days
    Then warm to serving temp (15 degrees CAMERA style!)
    Then hook it up to my hand pump and co2 Aspirator
    Flawless real ale!

    1. I forgot to add my 2p to the Keg flavor topic..
      Everytime I add CO2 to a naturally carbonated keg of UK ale (before I got my cask aspirator) the yeast character would disappear. Only to return with secondary natural fermentation. (eg if racked early)
      Remember: Dissolved CO2 becomes carbonic acid in solution. Carbonic acid might scrub or react with many reactive flavor compounds such as esters. (?)

  5. For a moderate cask experience I used the 5L mini kegs. It was enough for a small, afternoon gathering. They were a pain to clean after, and I wound up throwing them away.


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