What's going on in the last pour of a keg?

[silentknyght]

So, much to my chagrin, I’m all tapped out: all four of my kegs have been emptied. I’ve noticed a commonality between all of them, and I’m not sure I understand why it’s occurring. In each of the kegs, the final pour (sometimes the final two pours) is completely full of junk (trub, silt, etc.).

I clarify my beers with gelatin in the keg, usually. This means that, in the days following the gelatin treatment, I get a pour that’s very cloudy. Then it’s clear as glass from there on out. So, I imagine that the gelatin is pushing this silt / these particles to the bottom, where they’re exiting the dip tube.

But with the last pour being all junk, does this mean that each beer has a layer of “scum” floating on top, too? What is it and why does it get there? Or am I misinterpreting some other mechanic or effect?

[homebrew454]

I get the same thing and just always thought it was related to yeast settling out from the gelatin. I have been thinking of cutting a little off of the dip tube near the bottom to possibly avoid this but have been fearful of breaking the dip tube.

[wahoo]

watch what happens at the end of a siphon if there is some particulate matter when you are siphoning out of a carboy or bucket and you’ll understand. It’s not a layer of scum floating, but the particles on the bottom get sucked up when the liquid level drops.

[560sdl]

You have a tube pulling liquid from the bottom. The first few beers you are pulling some mud as it creates a clear “pocket” on the bottom. Eventually this stabilizes and as long as you do not shake or change pressure much, the pocket remains where you can pull clear beer through. When you pour the last few beers, the layer of liquid is about to mix the mud back up and thus the last few get cloudy. Very similar to how the waves at a beach are full of sand as they crash on the beach. The movement picks up the sand as the water gets shallower.

[mvsawyer]

I fine in the fermenter to allow less sediment in the keg.

[the_professor]

I used to experience that, but then I started cold crashing my beers while still in a carboy (almost always a secondary) and I gelatine fine it after it has been 4 days at 33°F and the chill haze has formed.
The gelatin drops the beer bright in a couple days, then I transfer it to the keg.
Yes, it’s a little bit of extra work but it pays off in that the only end-of-keg sludge (if any) amounts to well under 4 ounces…but more often than not, it pours clear and bright to the very last sputter.

[wahoo]

I sometimes do something similar to the Prof but instead of doing it in a carboy, I do it in a keg. Then I’ll use a keg to keg transfer to take the clear beer out of the “bright keg” into the “serving keg.” I don’t carbonate more than just a little until it’s in the serving keg.

[steppedonapoptop]

@mvsawyer

I fine in the fermenter to allow less sediment in the keg.

All it took was one clogged dip tube from gelatin that all my gelatin additions happen in secondary. Before I keg a batch, I put the carboy full of beer on the counter for at least one day to let any leftover trub/yeast settle - then siphon. The first pint is usually cloudy but that’s about it.

[silentknyght]

@560sdl

You have a tube pulling liquid from the bottom. The first few beers you are pulling some mud as it creates a clear “pocket” on the bottom. Eventually this stabilizes and as long as you do not shake or change pressure much, the pocket remains where you can pull clear beer through. When you pour the last few beers, the layer of liquid is about to mix the mud back up and thus the last few get cloudy. Very similar to how the waves at a beach are full of sand as they crash on the beach. The movement picks up the sand as the water gets shallower.

560sdl for the win! That’s totally what’s going on. Thanks. This totally makes sense. This wasn’t a great concern, but I just couldn’t envision what was happening; more a curiosity than anything. I had imagined that, since the dip tube goes down to the very bottom anyhow, there wasn’t any muck on the bottom…

[560sdl]

[quote=“Silentknyght”]

560sdl for the win! That’s totally what’s going on. [/quote]

Thank you, Thank you very much! What is the prize? :cheers:

[davhix]

@homebrew454

I get the same thing and just always thought it was related to yeast settling out from the gelatin. I have been thinking of cutting a little off of the dip tube near the bottom to possibly avoid this but have been fearful of breaking the dip tube.

Use a tube cutter like this one:

http://www.lowes.com/pd_331919-943-3523 ... facetInfo=)

and take 3/8-1/2" off of the end of your dip tube(s) and you won’t see it again. You lose a tiny bit of beer, which is sad, but no sludge.

[airlocksniffer]

The last pour is always the one where you say “Damn, that is really an excellent beer. I think I’ll have ano…D’oh!!”

[steppedonapoptop]

It’s always a guess to me as well. I poured a crystal clear pale ale yesterday and shared it with my wife. I went back for another half and all I got was mud. That was a nice batch