Ease my mind?

[TheMattTrain]

This is sort of a "is this infected" thread, but I don't have pictures, the beer's already kegged. Here's the story.

About 6 weeks ago I brewed an Irish Red Ale using Denny's Favorite 50 Yeast. I don't have temp control (I know, I know!) so the yeast fermented on the low end. We're talking 58 at the low and probably 62-64 at the high. I needed the carboy it had been fermenting in for three weeks, so I transferred to the keg and took a sample at the same time. It measured 1.030 and tasted pretty good, but was supposed to measure 1.015. The beer in the carboy had a really thin layer of film at the top which I've heard people call residual starsan and many other things. I racked from under it regardless leaving a good quart or two in the carboy. I vented the keg with CO2 to fill the head space and let it sit. I occasionally checked the pressure by relieving the keg via pressure relief valve and had gas coming out. It's now been in the keg for 3 weeks. I checked the gravity today and it was 1.020. Good enough for me. I tasted it and it tasted slightly sour.

I don't often drink samples with a lot of yeast trub floating in the beer, so I don't really know what that taste is. I have also never used Denny's Favorite. The LHBS was out of 1056. Is it possible that this sourness I'm getting is yeast trub rather than infected beer? The mouthfeel was about what I expected it to be. The only time I've had an infection before it made the beer very very light and dropped the gravity lower than I expected it to be.

Thanks for your help!

 

[VladOfTrub]

There is no such thing as yeast trub. So, whatever you have floating around is something else.

 

[TheMattTrain]

Dead yest? I thought trub was a general term for the stuff that falls out to the bottom during fermentation.

 

[VladOfTrub]

There is only trub. You mentioned in your post there was yeast trub floating around. There shouldn't be any trub in the keg. If you have trub carried over into the keg, the doorway for gram-n bacteria opens up.
There might be some yeast at the bottom of the keg that gets pushed out when a beer is drawn. Maybe that is what is happening, it is kind of normal. Is this the first time that you kegged beer?

 

[wonderbread23]

It sounds like you simply transferred incompletely fermented beer into the keg. I'd expect there to be a ****load of yeast in there as it sounds like it was still fermenting when kegged (judging from the 1.030 to 1.020 gravity drop). I'd bet against infection. More likely just funky flavors from an incomplete and unhealthy ferment. My money would be on acetaldehyde which can be green-apple like, but at times comes off like acetic acid.

 

[TheMattTrain]

Not the first time I've kegged, just the first time I've kegged a batch before fermentation was complete. I'm pretty sure there's a lot of trub sitting on the bottom, so I guess before I really judge this beer, I'll draw off the trub and dump that portion of it and try to get a better taste of more clear beer. I'll wait a few days because I just moved the keg today so I'm going to let things settle out. It's also getting cold, so more will probably drop out too. By the time it's carbed I should be able to draw a few pints with a lot of sediment in it, dump them, and get a good glass.

Thanks for the help.

 

[VladOfTrub]

By chance, did you prime the beer?

 

[TheMattTrain]

By chance, did you prime the beer?

No. I never prime. I force carb.