Motorized Mash Stirrer

[Normans54]

Hi all,

I am in the process of building a motorized mash stirrer for my Blichmann BrewEasy using copper tubing flattened into fins like this (H/T to @Lonnie-Mack):

Given that the manual for the BrewEasy says you should leave the bottom 2/3 of the mash bed undisturbed when stirring the mash because it acts as a filter for the wort, I want to make the length of the mash stirrer adjustable to account for different size batches and grain bills. My initial plan was to make the bottom part of the stirring arm out of 3/4" tubing and the top part of the stirring arm out of 1/2" tubing with the 1/2" tubing placed inside of the 3/4" tubing. I could then adjust the location of the stirrer by sliding the two halves of the arm lengths closer together/further apart and secure them with a shaft coupling like this. However, I have been unable to locate a shaft coupling that is big enough to accommodate a 3/4" copper pipe (much less one that can accommodate a second smaller pipe on the other end.) Can anybody suggest something other than a shaft coupling that I might be able to use for this purpose or another solution on how I can make the stirrer arm adjustable? Thanks!

 

[ITV]

One suggestion is to drill small holes in both the 3/4" & 1/2" tubing and once the length is adjusted use either a roll pin or cotter pin to fasten them together.

Another suggestion is to have several lengths of tubing each with the compression connector at the bottom and select the one that suits your needs.

Do you have a picture of the top end showing the motor that you are using?

 

[cyberbackpacker]

Your initial thought on height adjustment is a good one I think... why not just use 1/2" copper and then you can slide the shaft coupling up/down the stir arm as needed?

 

[Normans54]

Your initial thought on height adjustment is a good one I think... why not just use 1/2" copper and then you can slide the shaft coupling up/down the stir arm as needed?

Because I can't find a shaft coupling that can accommodate a 1/2" copper tube on one end and a 3/4" copper tube on the other end

 

[Normans54]

One suggestion is to drill small holes in both the 3/4" & 1/2" tubing and once the length is adjusted use either a roll pin or cotter pin to fasten them together.

Another suggestion is to have several lengths of tubing each with the compression connector at the bottom and select the one that suits your needs.

Do you have a picture of the top end showing the motor that you are using?

Though it will be a bit more work to make, drilling holes and securing the lengths together using a roll pin/cotter pin is an interesting suggestion. Thanks. I am, however, concerned that drilling holes into the stir arm will allow wort/water vapor into the paddle (which could make cleaning a nightmare.) To answer your question about the top end, I haven't bought the motor yet but I am probably going to buy this one: BEMONOC Garage Door Motor 12V DC Right Angle Reversible Electric Gear Motor 45 RPM High Torque

 

[cyberbackpacker]

Just use a Lovejoy half coupling so only one size of tubing is needed:

3/4" coupling

https://www.amazon.com/L075-L-Jaw-Coupling-Half-Interchange/dp/B01N5PVI6Y
1/2" coupling

https://www.amazon.com/Lovejoy-Stan...vejoy+l050&qid=1621296933&s=industrial&sr=1-2

 

[Normans54]

Just use a Lovejoy half coupling so only one size of tubing is needed:

3/4" coupling

https://www.amazon.com/L075-L-Jaw-Coupling-Half-Interchange/dp/B01N5PVI6Y
1/2" coupling

https://www.amazon.com/Lovejoy-Stan...vejoy+l050&qid=1621296933&s=industrial&sr=1-2

I've never used a lovejoy coupling before. How would it work here and how would it make it so only one size of tubing is needed?

 

[ITV]

I've never used a lovejoy coupling before. How would it work here and how would it make it so only one size of tubing is needed?

Lovejoy couplings won't give you the height adjustment that you need. They are intended to use with motor shafts (solid pipe).

 

[day_trippr]

I confess I only know what a scan of the Blichmann site provides wrt the BrewEasy system, but it leaves me wondering why one would stir the top third of the mash in what appears to be a recirculating system already?

Cheers!

 

[jerrylotto]

Maybe just raise or lower the motor?

 

[odie]

I confess I only know what a scan of the Blichmann site provides wrt the BrewEasy system, but it leaves me wondering why one would stir the top third of the mash in what appears to be a recirculating system already?

Cheers!

exactly...I don't see any benefit of stirring a recirculating mash. other than to break up dough balls. but then stir the whole mash.

 

[jerrylotto]

Wort can channel during recirculation especially if it is allowed to run dry which I do at the end of the primary mash. I generally like to stir up the mash when I'm sparging just to ensure I'm rinsing everything. It's also helpful if you're decoction mashing.

 

[odie]

K...I've been doing full volume BIAB. the mash does not run dry and the grain is below the surface so all the recirc spreads out evenly on the surface.

 

[jerrylotto]

A mash stirrer, motorized or otherwise, is never going to be useful to somebody who does BIAB

 

[Normans54]

A mash stirrer, motorized or otherwise, is never going to be useful to somebody who does BIAB

In addition to eliminating channelling, the main reason why I want to build a motorized mash stirrer is to reduce/eliminate temperature pockets. Without the constant stirring, those temperature pockets can cause in my mash temp to fluctuate wildly (which makes calculating a RIMS offset impossible)

 

[mbg]

I remember many years ago seeing some making such a device using an inexpensive ice cream maker.

 

[tracer bullet]

In addition to eliminating channelling, the main reason why I want to build a motorized mash stirrer is to reduce/eliminate temperature pockets. Without the constant stirring, those temperature pockets can cause in my mash temp to fluctuate wildly (which makes calculating a RIMS offset impossible)

I get it, but think there might be easier options. Extra insulation on the side of the tun so the middle / edges are more uniform, and a more even spread of the recirculated wort going in. I'd probably consider measuring the temp of the water going in, just moments before it hits the grain bed (i.e. the exit of whatever is recirculating it). It'd be a reasonably safe assumption with decent flow that the grain will be the same temperature.

 

[day_trippr]

Still not getting it, especially given the limited volume that can be stirred (1/3?). Unless a mash bed has been excessively tightened (usually via over-pumping) the recirculation should reach ALL of the mash, not just the top third. Also, churning the top third doesn't ensure the bottom 2/3s of the mash are still free of the perceived issues (hot/cold pockets, channels, etc).

But...different strokes, etc...Vaya con Dios...

Cheers!

 

[Normans54]

I get it, but think there might be easier options. Extra insulation on the side of the tun so the middle / edges are more uniform, and a more even spread of the recirculated wort going in. I'd probably consider measuring the temp of the water going in, just moments before it hits the grain bed (i.e. the exit of whatever is recirculating it). It'd be a reasonably safe assumption with decent flow that the grain will be the same temperature.

You would think that, however I have tried multiple different locations for placing my probe (including right at the mash tun return) and I still get MLT temperature readings that wildly fluctuate. As for insulation, I've taken multiple readings at different locations in the center of the grain bed and the temperature is never consistent so I don't think heat loss out of the side is the problem. What I do think is part of the problem is that the BrewEasy's autosparge is not a multi-port manifold like SS Brewtech does (which evenly spreads recirculated wort across the entire top of the grain bed) but rather is just a silicone hose with a float on it which results in the higher temperature recirculated wort to become concentrated in one place. However, replacing the sparge arm will only address part of the problem because it still results in the top of the mash being hotter than everything below. By adding a mash stirrer, I significantly reduce the impact that has and improve efficiency by eliminating channelling. Together, that will help my batches become more consistent.

 

[day_trippr]

[...]What I do think is part of the problem is that the BrewEasy's autosparge is not a multi-port manifold like SS Brewtech does (which evenly spreads recirculated wort across the entire top of the grain bed) but rather is just a silicone hose with a float on it which results in the higher temperature recirculated wort to become concentrated in one place. [...]

That ain't it. Everyone running a Blichmann autosparge valve is likely doing exactly the same thing. But as long as (1) one maintains sufficient fluid atop the grain bed and (2) doesn't try to recirculate at the limits it causes no negative effects at maintaining an even temperature through the mash. That's more a function of thermal input (recirculation rate plus appropriate hlt or RIMs temperature setting) vs thermal losses...

Cheers!

 

[aamcle]

I made one a few years ago from a car wiper motor an interesting project that gave me marginally better control but no noticeable improvement in the beers.

I stopped using if as it was just more to clean and maintain.

Aamcle

 

[Genuine]

How are you doing with draining your mash tun with that false bottom set up? I have something simliar however with silicone tubing instead of a hard line and with just water, it drains the mash tun fine. However in actual use, it doesn't drain out as much as I would like.