In my setup, after boiling, the wort goes to a pump, then through a plate chiller and then into the fermenter. I believe this setup is quite common.
Manually setting the water (or the wort) flow so that the wort into the fermenter is at the planned temperature isn’t easy.
Would it be possible to use the Brewpi to control the wort/water flow, so that when it reaches the fermenter, it is at the desired temp?
A thermowell could be added at the plate chiller output, connected to a Brewpi sensor input, and a controlled valve before the pump (and/or along the water line).
I see that Brewpi site is selling valve controllers for Brewpi, but it is not clear if they could be used for this purpose with the current firmware.
With the current firmware, this is not possible.
With the more flexible firmware we are working on, this could become possible.
However: the valves we sell are ON/OFF, they do not have position feedback. Controlling flow with them would be hard.
But to be honest, I don’t think we need to control flow. At full flow, the CFC is not good enough to cool from >80C to 20C. So what I usually do is recirculate until the output of the CFC is at 20C (the wort in the boil kettle is hotter), and then redirect the flow to the fermenter. That way, we only have to control the moment to toggle, which can be done with a digital valve.
You are right, I often do the same (recirculate the wort until the plate chiller output reaches the target temp). However, most of the times I use a Blichmann hop rocket, in this case recirculation is not the best option, as hops in the hopback need to constantly “see” a temperature that’s higher (70C-80C)
than what you get by recirculation.
It is still possible to regulate the wort flow to get 20°C out of 80°C, you can do this either by manually control the valves or by regulating the voltage of the pump.
However, doing this manually is tricky and often you miss the planned final temperature by a few degrees.
Anyway, since valves are just on/off, is control of the pump voltage an option?
Ahh the old not chilling to temps issue, I’ve had this problem for years due to living in the south. And after much trying this or trying that the only solid solution was to control the cold side of things. Once I moved to TX and was under some pretty strict water rules so I decided to build a complete closed loop chiller system and will never look back.
I run a sump pump in a cooler filled with ice water and am able to go from boiling to lager temps in a single 5min pass (12 gallon batch size). I run the cold side wide open and returns to the cooler and usually run the wort say 50% open. Like any commercial brewery the real way to dial this in is to control the cold side, once you can dial that it chilling is not a problem.
I plan to build a much larger Glycol setup in the next few months as my new nano (1bbl) comes in this week and I will need much more cooling capacity. I will be using that in the future for chilling both from kettle and in fermenter.
Cheers,
-Stephen