Grainfather, Brewmonk, and other all in ones with built in pump etc

[Moonlightweb]

So. Recently upgraded from a mash and boil all in one, to one with a pump in the base. Most of the instructions for the units with the pump say not to run the pump during boil. I guess because pressure + 100c liquid results in pump cavitation. So I measured the volume of the liquid (just water while testing) in the pump and piping and got about 300ml. So, after mashing and getting into the boil, there’s 300ml of wort not getting ‘cooked’ during the boil. And I guess the pump is not being sterilised during the boil either. So, disregarding the instructions I decided to run the pump during the boil for 20 seconds or so every 5-10 mins. Been doing this for the last few brews with no ill effects or apparent cavitation in the pump. is this necessary or should I stick with the instructions that say not to run pump during boil?

 

[The Baron]

I would follow the instructions as the reason I have been given not to use during the boil is the temperature rating of the pumps.
Regards the 300ml it technically does not need to boil as it only needs to reach pasteurisation temp for the wort to be safe to drink

 

[RoomWithABrew]

Agree completely with @the baron
No need to run pump during the boil, the liquid in there will get very close to boiling for the duration of the boil and when you run the wort through your chiller.
I actually run the pump on the way up to the boil around 80 celsius thru my counter flow chiller so that is sterilised / pasteurised. This works a bit better than turning it on at the end of the boil for me, something less to forget later. It gets hot wort through it as well when I turn on at the end of the boil and whirlpool with it. Good luck to anything that can live having been in 80 celsius liquid for a good ten minutes and then sitting cooling a bit and then getting reblasted.
I expect my wort is bacteria free after the mashout most likely.

 

[Agentgonzo]

The grainfather's instructions say to run the pump for 5 minutes at the end of the boil through the CFC to sanitise the CFC. This will also sanitise any wort that existed in the pump/tubing during the boil

 

[Eskdale]

I have the Guten, there is absolutely no need to run the pump during the boil.
With the tap on the return pipe in the off position no unboiled wort will get into the finished beer due to the vacuum.
I would hope in the interest of hygiene that on finishing brew day and the cleaning done that a hot alkaline clean of the unit, including the return pipe and the tap (where one is fitted) takes place.
I think the difference in the units is actually the impeller which defines the temperature rating. One is plastic, no more than 80C the other is ceramic or metal 100C

 

[RichardM]

I have a Braumeister. The pump cuts out at 80c. With the pump being mounted below the tap the tiny amount of unboiled wort can't get in to the fermenter without some extreme tipping action.

 

[Moonlightweb]

Meticulous cleaning. Five Star PBW run via pump through everything including the plate chiller for 30 mins. Scrub down of the kettle while running. Then three rinses. Even run it through the drain tap from the plate chiller out. Not had any pump trip outs with the occasional pump through during boil either.

 

[labrewski]

Using the brew monk for 2 years now never used the the pump during the boil
Never any problems