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?