Good timing, I was about to rack out!
So the red and yellow gadget on top of the pop bottle is
this.
To use the beer left in your fermenter, you simply gravity transfer into your pop bottle, then use the yellow pump on the device to push as much air as possible into the pop bottle. Then you serve with the cobra tap half cocked. Then pump a bunch more, then serve, then pump a bunch more...
Yeah, it's ghetto AF. I'll admit that. But that's where I live, so let me speak my truth. Don't judge.
It's a very, very hooptie way of doing cask ale...but it kinda is a beer engine. A seriously hooptie beer engine, but there's no denying that it really is a fantastically cheap and fantastically crap beer engine.
That said, it does allow you to put that last gallon in your fermenter to use. That's not a bad thing.
I hope you found this useful.
Edit: btw, it's dreadful as a line cleaner. Don't buy it for that.
