stout tastes off after some time in keg...O2?

[idbrewguy]

Hi all, I brewed a guinness clone from extract and thought I had nailed it. After a week or so in the keg, though, while it's still pretty good it's a little more fizzy (like a root beer) and slightly harsh, rather than smooth and creamy like it was. One thing I didn't know to do was burp the corny keg. Can O2 in the head space account for this sort of a change in taste?

 

[dcbw]

Not really, seems like it's normal beer aging. The harshness may be carbonic acid which will dissipate with a bit or time. The soda like bubbles mean that you haven't waited enough for full carbonation. Stuff in solution in the beer provides nucleation sites for co2, and that stuff will eventually drop out and the bubbles will become smaller. Also just might not have enough co2 in it.

For the creaminess, a lot of that depends on the recipe. What was it? Did you have flaked barley at all?

 

[idbrewguy]

The grains were already milled as part of a kit which listed 8 oz. Carafa II and 4 oz. Kiln Coffee. There was also 4 oz. chocolate (would that be as cocoa powder?). I read a bit about flaked barley, which apparently adds to the creaminess--is that your experience? Cheers.

 

[chickypad]

I wonder if you've overcarbed it for your tastes. Carbonic bite can be described as harsh, and if it's fizzy like root beer that sounds like fairly high carbonation. At what temp and pressure do you have it?

Edit: also did you burst carb it at higher pressure?

 

[idbrewguy]

10 psi at 36F. Temp is low for my taste, but I have something else in the kegerator that my wife likes colder. And I did burst carb a bit. Given all that, it does sound like I'm overcarbed--would burping that keg help at all, or will it just get right back up there if I don't change pressure and/or temp?

 

[chickypad]

That would be about 2.5 vols, so not crazy high but maybe more than you want for a stout. Depending on how you burst carbed it could be higher. You might try disconnecting the gas and burping it for a while and see if you like it better. Then the trick will be keeping it there if you're running other beers at 2.5. You could just add a little gas at a time as you dispense I guess.

 

[idbrewguy]

Based on your comment, I went and learned a bunch about vols--much appreciated. I'm going to burp the keg and take it off the gas for a bit, just to see if I can start recognizing the difference in taste with various levels of carbonic acid. Cheers to you and dcbw for the help.