eBIAB build. Constant stirring of mash instead of recirculating pump.

[markpmcb]

I'm in the process of upgrading my setup to an all in one eBIAB method. I currently mash and batch sparge in a converted cooler, and use an induction burner for the kettle. I decided it was time for an upgrade to simplify brew day. Cutting down on the cleaning is a big goal of mine, as well as the ability to do 5 and 10 gallon batches, and be able to step mash. (I can only do 5 gallon batches at the moment, and step mashing using a converted cooler is pretty difficult).

The community so far has been extremely helpful. I've been going through many of the posts on the topic, and I've slowly been planning out my build of the control panel and 20 gallon kettle with heating element.

Instead of using a recirculating pump that most of the all in one eBIAB builds have, I was thinking of building a constant mash stirrer. This mash stirrer would use an old windshield wiper motor for power, with a rake/paddle attached on the motor shaft. The motor would be mounted on the lid of the kettle, and can be plugged into a standard 120V receptacle.

My thinking is that I can have constant agitation during the mash. This will allow for better temperature control, as the heat will be distributed when the element is firing. It will also allow for good efficiencies. It will basically accomplish what recirculating the mash with a pump does.

Is there anything I'm missing that recirculating the mash with a pump does? I've read some things about clearer wort, but I'm not too concerned about that. I just want to make sure I have good temperature control when the element is firing, and get decent efficiencies. Because one of my main goals is simplifying brew day, I do not want to deal with cleaning the pump, lines, connections, etc.

 

[Birrofilo]

I suppose you want to do something of this kind:

https://www.polsinelli.it/agitatore-per-ammostamento-35-P1418.htm
I never saw this kind of setup with a bag, because I suppose the bag might end up in the paddles, you'll have to fix it very carefully. I agree conceptually it is better than a recirculating pump, but I suspect the reason why pumps are used in combination with bags is that bags are hardly compatible with stirrers.

Maybe you can find a way to fix the bottom of the bag to the bottom of the kettle through magnetic stainless steel and a magnet on the bottom exterior of the kettle, and use short paddles, and agitate very slowly.

When the mash is over, you take the cover with the agitator away, take the magnets away and raise the bag. Just thinking aloud though, it might be a very stupid idea.

 

[markpmcb]

That link you posted is very close to the idea I have in my planning! Thanks for sharing the link. Good point about the bag ending up in the paddles. The motor I have is slow, so I don't think that should be an issue. I'm also considering using one of those filters from Utah Biodiesel Supply instead of a bag anyways.

Thanks for the response. Not a stupid idea at all! Always helps to think out loud.

I just want to make sure I'm not missing anything important by not recirculating with a pump.

 

[RufusBrewer]

If you are going to go with a mash stirring apparatus, I strongly suggest you replace the bag with a one of the variations on the screen/drilled bucket themes.a Mny ways to go that route.

The thought of any moving objects with enough torque to pass through a mash, = potential disaster for me. Disaster that can go very wrong in many ways. A disaster that by the time you figure something is wrong, you have an unfixable tangled mess on your hands.

 

[Bobby_M]

Stirring within the basket will not necessarily distribute heat created below the basket into the mash. The best bet would be an auger shape that pulled upwards.

 

[markpmcb]

Thanks for the suggestions! Agreed that I'll have to think about the bag getting tangled if I decide to go that route instead of a basket.

Auger shape is an excellent idea. I want to make sure heat is being distrubted. A lot of your posts during my research and planning have been very helpful, Bobby. I'm currently eyeing this kettle/heating element/false bottom package.

 

[Bobby_M]

With a bag, you would definitely be in trouble in about 3 seconds of stirring. The bag goes everywhere. You'd need it to be kept taught perhaps with a dropped in ring of metal. You would also need a way to secure the lid from spinning and possibly reinforce the lid for strength.