I bought one of the first Gen4 65L's in the US and been using it for about 17 months and around 34 batches. I usually brew 5.75 gal batches, but have done 8 & 11 gallon batches as well. Tried every combination of PID settings, BT themometer and HED use that I can think of. Watched the David Heath and Kegland videos for PID settings. Researched PID settings. Nothing worked seemed to work, meaning chronic unsatisfactory mash temp stability...until trying the latest manual PID settings with the HED, no BT themo. I brew primarily for competition, so repeatability and predictability are very important. I've been brewing since 1996, so not a new brewer.
Also, The original false bottom fit so tightly that it would warp, which appeared to contribute to the mash stability problems and made the HED unusable. While I felt Kegland should have replaced the poorly fitting false bottom,
an email response from Kegland directed me to MoreBeer to buy a new one. The new false bottom helped a great deal (for some reason), and drops in and comes out easily, and works well with the HED (not warped).
- Neoprene jacket YES
- HED: YES
- BT probe: No (I have it, but not successful IMO using it)
- Temperature hysteresis setting: 1F
- Temperature differential setting: N/A (not using BT)
- Pump power setting: 100%
- Angle of ball valve or flow rate: about: pointing at about about 8 o'clock
- Heat power setting: depends on batch size, but 5gal usually 35%
- PID on/off: On (using latest manual default PID settings)
- Ambient room temperature: whatever is outside--does not seem to make much difference
Other factors to consider:
- 35L or 65L (I have a 65L Gen4)
- Power (mine is 240V/30A)
- Use rice hulls? (I use 4-8oz every time)
- Wort viscosity aids like Glucabuster (I use it every time--really helps the wort to drain quickly after pulling the malt pipe)
- As the stock setup allowed far too much malt into the boil, I use a BIAB bag in the kettle every time, and pull it before the boil
On Stuck Mashes:
My stock pump is powerful enough to collapse the grist and cause a stuck mash. Using rice hulls and being very careful to not open the ball valve too much (just get a flow going--does not need to be fast) is crucial. Also, and perhaps most importantly, I have found using the HED helps prevent a stuck mash a great deal, as the 'pull' on the grist isn't just in one, small, central place. Cellar Science Glucabuster also helps, and I can tell the difference when not using it.
On the BT thermometer:
I have tried the BT thermometer, but no longer use it. As Kegland says in their video, it measures grist mash temps where it matters most. However, in use I found it to lag the bottom temperature by a wide marge in step mashing, or if the strike temp was too low. To get the middle to catch up to the bottom, anything less than about a 10+F allowed differential does not work quickly enough to matter--the mash ends before the two reach the same temps. So, I tried a 15F and 20F differential to make things more speedy, as a 10C differential is mentioned in videos. The result was a beer with (appearant) attenuation that was way too low (did not come close to FG). My theory is that the bottom of the mash was too hot--too much differential led to different mash temps within the grist. I just need predictability and repeatability, and I know what results I get using only the bottom thermo reading, so that's now all I use.