My APA demanded so much hops that there was probably 5L of green sludge at the bottom of the fermenter by the end of the fermentation period. The wall of green extended well above the level of the tap – this would mean transferring the other 18L of ‘good’ beer to another receptacle before bottling.
I had heard the term ‘cold crashing’ but never really investigated it, thinking of it as an advanced technique used by lager producers. Well it’s certainly not advanced, and it’s saved this APA from a cloudy future. Seeing as my fermentation bin lives in a refrigerator anyway, I took the plunge and dialled the STC1000 down to 3degC after the fermentation was over. It took about 8hrs to reach this temperature, which is when I tossed in the gelatin. Gelatin you say? Yes, I dissolved a teaspoon full of plain jelly mix in hot water (not boiling, we don’t actually want jelly) and added it to the beer, giving the fermenter a quick shake. Apparently this is another fining agent, and causes the hop particles and larger bits of yeast to clump together and fall to the bottom. FFWD 24hrs and the beer is a lot clearer. A helluva lot. Bizarrely, though, the 5L of green sludge at the bottom seems to have shrunk to 4L. I was expecting it to have grown, as more of the stuff came out of suspension and settled onto it, but evidently the gak at the bottom condenses itself too.
Hop Sludge, 4L thereof
Anyway, brilliant news, I appear to have reclaimed a litre of beer from the clutches of the sludge monster. It’s easy enough to siphon the beer off the top of the green and into another fermenter, from which I can bottle. The green gunk seems to be sitting on top of the yeast trub, and because the hop matter is heavier, it is stopping it from clouding up at the slightest movement.
Verdict – cold crashing rocks*. I will use this method again, probably for every beer I make. The one drawback seems to be that because a lot of the yeast is being removed before it gets to the bottles, conditioning will take somewhat longer. So, I’m going to have to wait a while to taste this APA. It tasted, looked and smelled gosh darn divine at bottling – even if it doesn’t improve at all before I crack the first one open, I’ll be happy.
* This probably renders my incubator redundant before I even get to use it. I discovered, when I finally got hold of a manual, that it can only heat. It doesn’t do cooling. So cold crashing will require a separate fridge anyway. That’s a bummer because it had the potential to be majorly awesome.
Brew mechanics 