Recirculation Uncertainty

[Brewer #404298]

I used to run my pump during boil for recirculation, but then read that the high heat can burn them out. Everyone still agree that doing this is bad?

I understand the theory of running boiling wort through your plate chiller and such to sterilize. As you expect (even without the cold water running through the chiller), this drops the wort in the 10 gallon kettle maybe 10-20 degrees. Do you do this immediately prior to starting your boil timer (and then start timer once it is boiling again)? Does it matter when you do it (since it stalls boiling for a minute or two to get back up to temp)?

I do BIAB in a Blichmann 10 gallon with a Boilcoil. I have an ultimate sparge arm that I use for recirculation. I don't do sparging. This arm is a little unwieldy and probably overkill for my current set up. Any thoughts on something easier?

Blichman recommends that you buy their special fitting to put the temp probe for the Brew Commander inline in the circulation just downstream of the pump. But doesn't that conflict with my question #1 of not running the pump during boil?

Am I over thinking this?

 

[Minbari]

What is the purpose of recirc during boiling? The roiling of the boil will mix anything. Always a good idea at the end to sterilize the hoses and pump. But doesnt need to be boil temps. Above 160F will accomplish it

You do have to becarefull when pumping at boil temps mostly because the vacuum created will run the pump dry.

As for it "burning it out". Don't think that is an issue. Most pumps are rated for 250F and are magnetically coupled, so the motor doesn't see the heat.

 

[Limey]

Running the pump during the boil "can" cause the pump to cavitate - the liquid turns to vapor inside the pump. This can cause severe erosion to the pump impeller, and eventual failure of the pump. As Minbari stated, there is really no need to run the pump during the boil, just run it for a few seconds at the end of the boil to sterilize the pump and tubing.

If you really want to know about cavitation, read THIS.

 

[Donoroto]

I used to run my pump during boil for recirculation, but then read that the high heat can burn them out. Everyone still agree that doing this is bad?

I understand the theory of running boiling wort through your plate chiller and such to sterilize. As you expect (even without the cold water running through the chiller), this drops the wort in the 10 gallon kettle maybe 10-20 degrees. Do you do this immediately prior to starting your boil timer (and then start timer once it is boiling again)? Does it matter when you do it (since it stalls boiling for a minute or two to get back up to temp)?

I do BIAB in a Blichmann 10 gallon with a Boilcoil. I have an ultimate sparge arm that I use for recirculation. I don't do sparging. This arm is a little unwieldy and probably overkill for my current set up. Any thoughts on something easier?

Blichman recommends that you buy their special fitting to put the temp probe for the Brew Commander inline in the circulation just downstream of the pump. But doesn't that conflict with my question #1 of not running the pump during boil?

Am I over thinking this?

@Minbari We run the pump to sanitize the chiller and related tubing.

Running the pump at boiling is fine for many pumps, but not all. You need to check the specs on it for temperature. But not running it (= not sanitizing) is far worse. I run the built-in pump in my brewzilla for each and every boil, hasn't melted yet.

While cavitation is an issue, I suspect little to no air/gaseous phase reaches the pump - but this is just a guess, maybe wishful thinking.

I wait to about 15 minutes into the boil (after most of the DMS has been evaporated), then run the pump for a minute or two to get very hot wort into my counterflow chiller (no cooling water yet). Then I shut it off, and leave the hot wort to sanitize it. I do this again with 10 minutes left in the boil, then again at the end of the boil, but this last time after I let it run a minute or two I turn on the counterflow cooling water to bring the boil pot down to 180 or so. If there are whirlpool hops, that's when I do them, otherwise I re-route the cooled wort into the fermenter and start on that.

Each time I run the pump I kill the boil, but only for 2-3 minutes until it catches up again.
I do not deduct from the boil time those few minutes spent not really boiling. At 190 F it is hot enough to keep doing those things the boil is expected to do.

 

[Craigerrr]

I run my pump to circulate through counter flow chiller towards the end of the boil (also have a Brewzilla).
Just prior to circulating I run HOT tap water through the chilling side of the CFC to minimize the temperature drop in the wort returning to the kettle.
Losing the boil for a few minutes isn't critical.
It is still hot enough that it won't have an affect on boil hop additions, and you can always adjust your boil off rate if you find you are losing the boil for a long enough period of time to affect that.

 

[Brewer #427409]

I used to run my pump during boil for recirculation, but then read that the high heat can burn them out. Everyone still agree that doing this is bad?

I understand the theory of running boiling wort through your plate chiller and such to sterilize. As you expect (even without the cold water running through the chiller), this drops the wort in the 10 gallon kettle maybe 10-20 degrees. Do you do this immediately prior to starting your boil timer (and then start timer once it is boiling again)? Does it matter when you do it (since it stalls boiling for a minute or two to get back up to temp)?

I do BIAB in a Blichmann 10 gallon with a Boilcoil. I have an ultimate sparge arm that I use for recirculation. I don't do sparging. This arm is a little unwieldy and probably overkill for my current set up. Any thoughts on something easier?

Blichman recommends that you buy their special fitting to put the temp probe for the Brew Commander inline in the circulation just downstream of the pump. But doesn't that conflict with my question #1 of not running the pump during boil?

Am I over thinking about Traffic Jam 3D game?

You're right on track with your thinking about running the pump during boil.

Recirc during Boil: Yes, most brewers avoid running the pump during a full boil. The high temperatures can damage them, especially if not rated for boiling wort.
Plate Chiller Sterilization: Briefly recirculating wort through the chiller before starting the boil is a great way to sanitize it. A 10-20 degree drop is normal for this process.
Timing the Recirculation: It doesn't matter much exactly when you do the pre-boil recirculation. A minute or two to reach boiling again is fine. The key is to ensure the wort reaches a rolling boil before starting your boil timer.
BIAB Setup: The Ultimate Sparge Arm might be a bit much for BIAB. You could consider a simpler dip tube with holes for better wort movement during the boil.
Temp Probe Placement: Blichmann's recommendation for the inline probe placement conflicts with not running the pump during boil. It's best to position the probe in the kettle itself for accurate temperature readings during the boil.