Brew Day Notes

0535 Start dough-in

0545 Start mash rest

0605 Start mashing

0615 Looking quite gloopy, adding 50g (large beaker) rice hulls. Pausing mash tracker while working them in.

0620 We‘re off again. Running a bit more freely now, able to get small fan from centre pipe.

0715 Mash almost done. Adding those rice hulls was a good move, it‘s been moving more freely ever since and I‘m hoping for some good numbers today. Last time around we had 25.5 litres before sparge (no rice hulls though) and 1.059 (1.042 @ 61.2℃), this time it’s 1.062 (1.046 @ 61.0℃) and 25 litres dead. Numbers looking good!

0730 Heating to 75℃ for mash-out

0737 Start sparge

0745 Sparge done, heading for boil. SG 1.041 (1.024 @ 61.9℃) is about the same as last time – 1.042 (1.024 @ 64℃) – was expecting 1.044 so 3 points down. Volume 28 litres, down approximately half a litre against last time.

0820 Start boil tracker, 60 minute additions in. Time to prep the Fermzilla.

0845 Couldn’t get one of the top disconnects to seal properly. After two attempts and one replacement it seems I’m over-tightening them and causing the rubber seal to either become deformed or push into the thread on the lid, leaving the threaded plastic to do the job of sealing. Refitted a new disconnect more loosely and it’s fine now. Lower FV connections / joins all tight.

0915 About 15 minutes left to run, chucking in the Trubinator and chiller coil, pausing while boil resumes. Post boil readings (taken prior to cutting in) are 25 litres, 1.055 (1.026 @ 82℃). Last batch was 1.054 (1.040 @ 55.8℃) so we’re quite consistent, and again north of the expected 1.047. 

Think I may have added the last 15g of Tettnang 5 minutes early, making them 15 minute additions instead of 10. Oops. Will make sure I stop boil a couple of minutes early. 

0925 Heaters off, starting chill.

0930 Return temperature is creeping up, something’s wrong. I suspected the pump had jammed, but it appears that water supply to the property has been cut off. Tank temperature 76℃ and falling very slowly.

1005 Water’s back on, resuming chill. Tank temperature 70℃. 

1015 Return temperature hovering about 23℃ now, starting transfer.

1045 Transfer finished, bang-on 20 litres in the FV. Topping up with 5 litres Celtic Spring, OG now 1.042 against predicted 1.047. Should make for 4.5% ABV but with 25 litres in the Fermzilla I will fit a blow-off bottle.

The slurry portion of the yeast starter was pitched into roughly 22℃ wort after acclimatising it to room temperature throughout the brew day. I ditched the waste liquid first thing this morning after it had separated nicely in the refrigerator overnight.

1200 Clean-up finished, FV in fermentation chamber and blue Tilt attached. We’re still cooling to target 16℃ (presently at 21℃) and it may just be my imagination, but I think I can see fine bubbles already making their way to the surface.

Although the blow-off bottle is already crinkling slightly due to the temperature dropping, I’m going to use a small CO2 canister to give the whole rig some positive pressure and avoid damaging the Fermzilla if the blow-off bottle proves insufficient as a buffer.