lauter rakes

[Brewpastor]

I have been posting my ideas of using a stainless steel oven rack as the basis for a paddle/rake for my tun. Some of you have wondered about this so I thought I would share what I know about how these rakes work and why they are used.

Many lauter tuns in commercial set-ups have an automated raking system in their tun. This is a set of knives that rotate during the sparge to cut the mash and thereby keep it open, and uncompacted. This keeps set channels from forming while at the same time creating and closing new channels for the water to move through. This helps insure all the grain is washed and no wort is left unharvested.

The knives run vertically across the tun and rotate around a central axis. The knives are set so the blades on one side track between the blades on the other. With this set up, one side is constantly filliling in the other. In addition to this verticle action, horizontal cutting takes place. In a commercial set-up each blade has a series of horizontal ridges that cut and lift the grain on a horizontal plain. With my oven rack set-up I think the brace/cross support rods of the rack will serve this horizontal function nicely. They would provide a horizontal channel that would help water flow throughout the grain bed.

In these set-ups the knives run down to just a couple inches above the bottom of the tun. This allows the dough bed to remain undisturbed and allow good grain bed filtration to be maintained.

So that is what I know, more or less. Not really needed on a HB level, but since I do want mash mixing capability anyway, I might as well utilize this other function.

 

[Reverend JC]

With all of that talk of knives and cutting i would name your device the "Mash Ninja"

You can use that name for only $3.50

bargain, i know!

 

[Brewiz]

BP, First off sorry to hear about your Sister's passing and I would like to offer my deepest sympathies.
Now to the rakes, I have seen them in work at local brewery that some friends of mine own and my question is this: for us that do small batches 5-10 gal are they worth the time and effort to set them up??

 

[Brewpastor]

No, I don't think so. I am on the margin of usefulness. I typically am using 50# of grain and because of my tun's design I have a really deep grain bed. So I think it will help me. But is I was doing a 10 gallon batch I wouldn't bother.

Unless you are like me and just like toys and projects and will do whatever is needed to justify them!

 

[Brewiz]

Unless you are like me and just like toys and projects and will do whatever is needed to justify them!

Yeah I love the toys too, and now you have giving me another project to line up. I was thinking about using a grill "Rotisserie" motor and some sort of rake set up.

 

[Baron von BeeGee]

That makes sense to me. I thought you were thinking of a "mash mixer" a la the Kaiser.

 

[Kaiser]

That makes sense to me. I thought you were thinking of a "mash mixer" a la the Kaiser.

Brewpastor, Do you mash and lauter in the same vessel?

If you are using the grid style oven rack, I would be worried about actually spinning the mash, thus creating wort movement that can easily distiurb your lower grain-bed unless you don't lower it very far into the bed. You could try to remove some of the wires from the rack to make it easier for the mash to flow through.

Kai

 

[Brewpastor]

Brewpastor, Do you mash and lauter in the same vessel?

If you are using the grid style oven rack, I would be worried about actually spinning the mash, thus creating wort movement that can easily distiurb your lower grain-bed unless you don't lower it very far into the bed. You could try to remove some of the wires from the rack to make it easier for the mash to flow through.

Kai

That is what I plan. Basically it will be a comb with an extra horizontal bar about half way down. I will set the teeth of the comb so they are a few inches above the manifold. I also will be doing whatever I have to to make the rake rotate VERY slowly, maybe something like 10 rpms. Also, the knives/teeth/blades are almost 2 inches apart on the rack I am planning to use. I think it will be OK, but please let me know if this seems to be a folly.

 

[John Beere]

I found this linked off of the Brewboard:

http://good-times.webshots.com/photo/2023086930099049245psvZkK

Mash Mixer made out of copper tubing... quite a bit different than what you decided on but looks simple enough to make. Looks like its powered by a motor out of an ice cream churn.

 

[EvilTOJ]

Would an ice cream maker motor have enough power to it? They move slow enough, but it doesn't seem like it'd have enough oomph to cut through a huge grain bed.

 

[John Beere]

Would an ice cream maker motor have enough power to it? They move slow enough, but it doesn't seem like it'd have enough oomph to cut through a huge grain bed.

I've seen it referenced so I know others are using them but I have no idea how efficient they are...

 

[Kaiser]

Would an ice cream maker motor have enough power to it? They move slow enough, but it doesn't seem like it'd have enough oomph to cut through a huge grain bed.

I think it would be perfect since it is powerful enough to cut though ice cream and moves slow enough to avoid excessive aeration.

Kai

 

[D*Bo]

Check out Jemco, they have some gear head motors.
P/N 176049 24V 340mA 1.8 RPM 6000g-cm torque $21.95
there are several options for power supplies. Open frame switching, regulated table top, unregulated table top. Plenty under $20

 

[Kaiser]

6000g-cm torque

This doesn't seem to be enough touque for stiring a mash. It's only 0.4 lbft.

Kai

 

[Pabst Blue Robot]

This doesn't seem to be enough touque for stiring a mash. It's only 0.4 lbft.

Kai

Time to hook up the ole' 427 and some crazy gearing!

:fro:

 

[D*Bo]

I forgot to convert that to see what it actually was. I had a smaller project that was planned for. I don't know if they have anything bigger.