Mash tun recirc question

How consistent does recirculation of the wort in the mash tun keep your temperatures throughout the mash? Hot and cool spots, etc. I don't want to mess with a heat exchanger in the tun but am interested in controlling the consistency throughout. I have a direct fired tun.

I recirculate using a RIMS. After around 5 minutes it seems that all my thermometers (3 spaced in the process) are pretty close to dead on.

Thanks for your response. RIMS is just pumping the wort back into the top of the mash tun, correct?

RIMS (Recirculation Infusion Mash System)

Yes, it gets recirculated thru the lid with usually a spray ball inside.

Johnnyhitch1 said:

RIMS (Recirculation Infusion Mash System)

Yes, it gets recirculated thru the lid with usually a spray ball inside.

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Is spraying OK. what about oxidation? Wouldn't it be better to just let run in slowly at just below the surface level of the mash?

I have been recirculating the mash wort for many years with a direct fired tun. I ended up making a circular manifold
which I adjust to touch the surface of the wort. About 1.5 years ago I switched to BIAB. It works great.

Thanks for the replies. I'll work on something along these lines. Just finished automating the burner for the HLT so the MLT will be next.

mblanks2 said:

Thanks for the replies. I'll work on something along these lines. Just finished automating the burner for the HLT so the MLT will be next.

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I would (and did) automate the MLT not the HLT, and run my pump to recirculate the whole time.

I have thought about doing this, I scored a pump off craigslist that came with a pot and other stuff, I have never hooked it up. I need to build a stand for everything too.

RoadKing said:

I would (and did) automate the MLT not the HLT, and run my pump to recirculate the whole time.

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I will be looking into the pump for MLT also, but I wanted to control the temperature of my HLT for the fly sparge process first. This was the part I found to have the most difficulty maintaining.

mblanks2 said:

Thanks for your response. RIMS is just pumping the wort back into the top of the mash tun, correct?

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No. Although the name doesn't indicate this, RIMS (and it's "cousin" HERMS) imply MORE than just simple recirculation; they both pull wort out of the mash, heat it outside of the mashtun and then return it back to the mash.

RIMS systems use an external electric element as the heat source while HERMS systems use a copper coil heat exchanger placed in the HLT or a dedicated heat exchange vessel.


Constant recirculation isn't the best thing for your wort quality; you extract a lot of things that shouldn't necessarily be extracted. If you've already got a direct fired MLT a stir motor might be a better option.

If you go with either option you will speed up conversion so you'll want to start performing the iodine test on your mashes and probably decrease your mash times so you don't end up with overly thin, highly attenuated beers.

If you go with the recirculation option, I'd recommend just recirculating when you need it (as the temperature starts to stratify) and not continually throughout the entire length of the mash.


I recirculate every 15 - 20 minutes for 3 or 4 minutes just to keep the temperature even (makes it easy to grab a gravity and iodine test sample, too); my mash is double walled insulated stainless though so it holds heat fairly well.


Adam


Adam

If you've already got a direct fired MLT a stir motor might be a better option.

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This was my original thought as was recommended to me by my LHBS owner but it was recommended in another thread to just get a pump. He had a design that he used on his original homebrew system years ago that I got the parts list from.
He now has his own brewery with rake system and makes excellent beer on a 1000 gallon system. I should listen to him more closely I think.
He's already won two gold medals in the past 3 months.
I want to automate the firing of the tun like I have just done for my HLT and the rake would keep a good mix so the temperature stayed consistent.
So if my first all grain mash efficiency was 84% with a 60 minute mash time and I added the rake what would you recommend as a starting point for the iodine test?
Would I see increased efficiency from where I'm currently at? My main concern is consistency in the control of my process. I'm happy with 84%.

biertourist said:

Constant recirculation isn't the best thing for your wort quality; you extract a lot of things that shouldn't necessarily be extracted. If you've already got a direct fired MLT a stir motor might be a better option.

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I can't say I agree with this. I don't know what else is going to be extracted
by recirculating or how it will be detrimental to your brew.
I recirculate the whole time with a direct fired MLT to help keep a
consistent temp and keep enzymes evenly dispersed throughout the mash. I will also stir every 15 mins. or so to make sure the grain is in full contact with enzymes.
Also,there is a big difference between a pro brewer having to use using rakes
to keep a mash stirred and a hobbyist who can achieve the same thing with a pump and a large spoon or paddle.
Just my 2 cents....

Agree. Biertourist, Why do you think moving the mash through a pump is any different than leaving it in tun?