Aug 202106Fri

Shaky Start to Yeti

SG 1.072 19℃ started wisdom

Not the greatest of brew days. Everything was going well until it was time to start the transfer to my SS Brewtech Bucket, when the flow became a dribble after barely a cup of wort had gone across. I decided that the inline Bouncer filter was to blame, or rather my use of too fine a mesh, when I noticed that I’d fitted the filter the wrong way around – not that this should actually matter in terms of flow.

Regardless, I swapped out the mesh for a larger one and corrected the filter’s orientation, but there was still nothing coming out so I decided to remove the filter altogether and risk the odd bit of trub in my FV. When still nothing came out I switched the lower left-hand valve to recirculate, and still nothing. Looks like the pump was jammed. With no means of pumping my wort to the bucket via the chiller it was either a case of using the racking cane and muslin filter, or I could just remove the centre pipe and set the right-hand valve to ‘drain all’.

It had been a long day so I went for the latter option, knowing that I’d get a tremendous amount of trub as a result but at least there would be practically no wasted wort, even if I’d have to spend additional time chilling. In hindsight I should have swapped the bucket for the Fermzilla at this point, since I could have used the collection jar to remove some trub once it had settled, but that’s hindsight for you.

I transferred to FV and got about 21 litres against my planned 15, so I don’t mind if I need to leave 2 or 3 litres behind. Good job I can rotate the dip tube on this vessel. The bucket went into the ferment fridge dialled to 22℃, which was the temperature of my patiently waiting yeast starter. Took a couple of hours to get there, then I pitched my yeast and dialled in 19℃ for optimum fermentation. Strong stream of bubbles by next morning tells me the yeast at least is happy – let’s just hope there are no off flavours from all that trub.


  • don’t bother with a filter when transferring to FV
  • don’t risk stopping the pump on high gravity, sticky brews
  • if expecting lots of trub, use the Fermzilla

Brew Day Notes

08:20 – Started dough-in, water level at 25 litres with chiller and link pipe filled.

08:35 – Dough-in finished, heaters to 65℃ for mash rest. Needed quite a bit of tamping to get everything wet.

08:59 – Starting mash. Internal levels measured at 30 litres. Wort is light at first but quickly begins to darken.

09:09 – First stir, check for dough balls. All good. Definitely seeing less material making its way through the new screen than before, but flow also appears restricted and stirring doesn’t drop the level in the malt pipe as much as with the old mesh. Sucking air pretty soon, need to cut back on the centre pipe flow.

09:39 – Second stir, and this time I’m seeing the levels in the malt pipe drop nicely as the mash is agitated. Cut flow to centre pipe for a minute or two and we have balance, so I check the levels: 29.5 litres on the internal scale. On resuming flow I’m able to use the centre pipe more without the levels dropping, which should help to get better mash efficiency. 15 minutes to run.

09:59 – Mashing complete, heating to 75℃ for mash-out. One objective here is to make the viscosity of the mash thinner by raising the temperature so that sparging is easier, but we’re not sparging on this recipe. Still, it may allow the mash to drain better which will help minimise losses.

10:04 – Switching to manual heater control mode since mash mode can’t shift the temperature above 72℃. Need to be careful here to avoid 77℃ and with it off-flavours from tannins. Heaters at 65% for now.

10:06 – Starting mash-out at 75℃, heaters back to mash mode to see if they’ll hold it.

10:16 – Mashing complete. Quick check of levels and pre-boil gravity: 29.5 litres and 1.069 (1.049 @ 67.4℃) against Brewfather’s predicted 1.077. Seven points short isn’t great.

10:22 – Raising malt pipe for drain, heaters to 100% for boil. Boil volume is 19.75 litres against Brewfather’s 20.5 which means I’m short on volume and gravity. Balls.

10:49 – Boil tracker started, 60 minute additions in.

11:18 – 30 minute additions are in. 

11:33 – 15 minute additions in, quick stir to release high tide hops, cut in chiller to sanitise. It’s already filled so won’t impact levels, which I’ll measure at the end.

11:50 – 5 minute additions are in. Plumbed in the transfer filter while circulating through chiller.

11:54 – End of boil, start chilling. Temperature 99.3℃ in tank. The yeast starter is at 22℃ so that’s roughly what I’m aiming for in my chiller return temperature before I start transfer.

12:10 – Return temperature is down to 25℃ so I’m starting transfer now. Quick check on the levels shows an optimistic post-boil volume of 17 litres / 36.6℃ (tank temp) against Brewfather’s 18.13. Probably about 1.5 litres short.

12:30 – Nightmare. Pump seems to have seized, possibly as a result of the transfer filter clogging, being in the wrong way round, then the larger grade replacement mesh clogged too. In the end I had to remove the filter, centre pipe and transfer using gravity, getting a load of crud into the FV as a result. Still, looks as though there’s no trub / chiller loss with a fermenter volume of 21 litres versus Brewfather’s predicted 15 litres. Post-boil gravity 1.072 (1.070 / 27.3℃) against predicted 1.088 – double balls. Be lucky to scrape 8% ABV at this stage. Not pitching yeast into FV at 29.5℃ so off to the ferment fridge until you calm down, with a quick blast of oxygen on the way so that at least I can clean everything.

13:50 – Cleanup finished. FV temp 27.8℃.

18:00 – FV has been at 22℃ for an hour or two, time to pitch the yeast starter and throw in a Tilt.