May 202102Sun

Started Cold-crashing, stole Yeast

SG 1.012 18.9℃ cold-crashing WLP001 yeast

This brew was originally started as a low-cost experiment to see if I could do something with WLP001yeast harvested from Twisty Listy, and judging by the way it’s been fermenting these past 13 days that seems to have worked well, so now my thoughts turn to the next steps.

I’ve decided to split the batch, and dry-hop one half the traditional way in a regular bucket as opposed to a conical so as to get maximum exposure to the hop pellets instead of compacting them into small footprint. The other half will be exposed to the HFR method, or Hot French Randall. More on that later.

First it’s time to cold-crash so that I can get virtually all the yeast to drop out, and I’m doing this for two reasons; I want to harvest the yeast so that I can try this particular strain of WLP001 a third time, and I want the half of the experiment which will be traditionally cold-crashed to have as little yeast as possible. I heard somewhere that yeast interacts with the hops in a negative way (not just by venting hop oils along with any CO2 produced) and I haven’t tried it this way around before, so it’s worth a shot.

Having racked from the SS Brewtech conical bucket to a regular plastic bucket I fitted it with Bag Thing (recently revived with some duct tape after the tube came loose) and put her in the brew fridge, Inkbird set at 4 ℃. Meanwhile I used the turkey baster to remove the last dregs of beer from between the conical’s dip tube and the top of the yeast cake, before spooning some gorgeous, clean yeast into a sanitised glass jar, previously home to 453g of Manx honey. The jar filled in no time and there were probably another two jars left behind in the fermenter, which is pretty amazing considering that I originally received this yeast as two sachets of mayonnaise and had already used that to brew 22 litres of amazing IPA. If only hops could be persuaded to reproduce like that …

A final note on the state of the brew so far, and I must say that I was surprised at the darkness and the clarity, if to the aroma. There’s a definite umami quality to the nose, something between nuttiness and yeastiness, as well as a thin film that stays behind when the beer is swirled in a glass. I’m putting this down to the simply ridiculous amount of yeast that was in the bottom of the FV – over 3 lb – and I’m tempted to say that the yeast may not have fully finished clearing up after itself. I’ve had the filminess (and, to a lesser degree, the yeasty taste) in other brews which turned out fine, so I’m not worried. Cold-crashing will do its thing, and the hops are sure to mask whatever’s left over.

In terms of alcohol, in 13 days we’ve gone from 1.045 to 1.012 which equates to 4.3% ABV against Brewfather’s expected 5.0%, so not quite there yet. Those values are as measured using my traditional hydrometer – if we go by Tilt then we’re looking at 1.007 from 1.041, giving 4.5%. Also a bit short of the mark. Should I have left this in the FV longer? According to recipe I was supposed to dry-hop yesterday but we had a late night on the shooting range, and besides, I wanted to try cold-crashing and harvesting that yeast, so I figured an extra day wouldn’t have hurt. Going forward maybe I should have taken a manual gravity sample and based on the outcome waited a bit longer, but hey, it’s a learning curve.

After giving her a couple of days in the cold (aiming for 4 ℃) I’ll split the batch for traditional dry-hopping and HFR, with each half filling a 5 litre keg and, hopefully, around 10 x 500 ml bottles.