Direct fire RIMS vs direct fire, auto-stir mash?

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Hex

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Can't decide which way to go with all grain wort extraction.

I could get a pump and plumb my rig for RIMS, or I could convert a BarBQue rotisserie motor to automatically stir a direct fire mash.

I've got a Blichmann false bottom in a 7.5 gal stainless stockpot.

Which way to go? pros? cons?

Flavor differences? Time savings? Both will support step-mashing (which is my ultimate goal).

If I use auto-stir Mash, I will still have to transfer the mash to the lauter tun. I will also have to pre-heat the lauter tun.

If I use RIMS, I may have other issues to deal with recirculation (pump, lines, stuck sparge).
:mug:
 
I have a kegge and 15 in FB. I've been trying to figure this out too. I think the direct fire recirculated system is a good KISS system. It has less stuff to clean. I'm thinking I'd put a temp probe inline with the pump so I could adjust the burner too.
 
I had a herms and went to direct fired and a stirrator. Just didn't like the time it took to step and mashout with the herms and was never able to get past temp stratifiaction in the mt with my herms setup. I've talked to other folks that didn't have these issues so it may have been my design. My efficiency went up to the mid 80's with the stirrator and I get < 2dgf temp variation top to bottom in the mt. Direct fire allows me to step and mashout with a 1dgf rise per minute easily. Overall my system is less complicated since I abandoned the herms design. I know your talking rims but the 2 are not that different.
 
I had a herms and went to direct fired and a stirrator. Just didn't like the time it took to step and mashout with the herms and was never able to get past temp stratifiaction in the mt with my herms setup. I've talked to other folks that didn't have these issues so it may have been my design. My efficiency went up to the mid 80's with the stirrator and I get < 2dgf temp variation top to bottom in the mt. Direct fire allows me to step and mashout with a 1dgf rise per minute easily. Overall my system is less complicated since I abandoned the herms design. I know your talking rims but the 2 are not that different.

How do you keep your stirring paddle from taking out your pickup tube? What RPM does it spin? Pictures? Also, what are type/BTU is the burner you use to fire the mash tun?
 
The pickup tube is as close to the bottom & side of the keggle as I can get it. I use a false bottom with a braid under that and a nylon paint strainer bag cut to fit and clipped to the top of the fb. The paddle is within 1/4" of the fb and 1" from the mt edge. Right now I'm at 20rpm, 30 rpm would be the optimum based on my research. Don't know the burner btu, but it low pressure propane one of those that has perimeter holes and holes in the spokes, must be about 10-12" diameter.
 
The pickup tube on my keggle is what will cause me grief since it's not all too close to the false bottom. What are you using as a paddle and motor?
 
I come off the wall of the keggle with 2 stainless elbows to get it on the bottom. The paddle is fabricated from scrap stainless, nothing fancy 2 vertical blades about 2-3" wide, probably 16ga. with cross-pieces to tie them to a keg dip tube for the center shaft. I have a pivot in the center base of the keg that holds the fb in place as well as providing a bearing for the bottom of the stirrator center shaft dip tube deal. I use a small gear motor, it's about 20rpm I have to help it start when I first mash in, as I fill the tun with grain and underlet the strike water. I have another motor about 45 rpm that had the kahoonas to start on it's own but it causes too much turbulence. Got one motor at Herbach & Rademan, the other at Surplus Sales of Nebraska, both I found on the web googling for fractional hp gearmotors
 
I recirculate with a pump through a manifold and use direct heat. No need to stir, the wort recirculation prevents scorching on its own.
 
Great info, thanks especially the detailes about fractional hp gear motors. I too like the auto stir idea. Seems like a more natural approach.

I'm using a separate mash/boil kettle and lautering tun, so no stirrer issues-no dip tube, just mash transfer to lauter tun.

Randy Mosher has a drawing in the back of Radical Brewing p. 295 that shows his set up, auto stir, gravity mash transfer, pump transfer of lauter to boil kettle.
 
BTW, I load tested my inexpensive BBQ rotisserie motor over the weekend, probably not enough torque for even '5 gal'-14 lbs grain.
 
Hmmmmm...I wonder if I could put two paddles in on each side of my dip tube so I wouldn't need to modify it...I'll have to look into that.
 
BTW, I load tested my inexpensive BBQ rotisserie motor over the weekend, probably not enough torque for even '5 gal'-14 lbs grain.

Go to the scrap yard and get an old windshield wiper motor. I've seen a few people use them. I figure if it's too fast, just attatch a chain and sprocket to reduce the RPM at the paddles. The chain would make hooking up a double paddle system pretty easy for my system.
 
I just found an old motorized ice cream maker on craigslist for $10! That should have the power to mix a big grain bill.
 
The ice cream makers I have are too loud. I'm indoor, stove-top mash.

I guess I could drag a car battery in for the windshield wiper motor, or a 12v transformer...

Like to keep it clean on 120v household.
 
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