Recirculating Mash Temp Question

This is my current setup. I have temp readings coming out from the tun and also of the mash itself. I've noticed that when I want to do a protein rest or increase the temp of the mash before sparging I don't get good uniform mash temperatures.

A made up example: The exit temp will be 155, the temp re-entering the mash will be 153-154, but the bulk of the mash can be as cold as 135-140. Unless I stir the mash bed I notice I never good even temperature. Do other people who direct fire their mash, use a RIMS, or HERMS system see the same type of issue? Naturally I don't want to stir much/often/ever after getting my bed settled.

I don't have a picture of my return. I usually just have silicone hose which hits a piece of foil and keep the water level a few inches above the bed. As I write this I feel it might be necessary to have a whirlpool by re-directing the inlet to the side of the kettle? If this is the answer, any suggestions on how to best do this with minimum splashing and not disturbing the bed? I recall someone once posting a 1/2" SS flexible hose with a female end. Anyone know where to find such a thing?

Thanks for any suggestions!

I would really like to answer your question, but I use a single tier system with two sanke's for hot liquor and mash tun, and a 20 gallon brew kettle. I experience exactly the same thing you are going through, with about the same spread. When we return the wort it goes out of the pump via silicone tube and goes into a copper manifold in the shape of an "H", giving me 4 exit holes (1/2 inch copper 90's) always just below the surface of the wort. We constantly hit preboil gravities and such and have produced great beers over the course of the last 4 years of all grain brewing 11.5 gallon batches. We insulate the tun with a water heater blanket as well. I guess in closing we've just come to kind-of except what we have , as we can get about any temperature we want if we probe around for it. Crazy I know and of course absolutely no help to you, but damn good question. Simie

You guys are starting to scare me... Temp fluctuations between 135 and 155?? That's just ludacris and the kind of thing that a recirculated mash is SUPPOSED to solve; if it doesn't solve that problem then I don't think the extra complexity is justified just for increased wort clarity.


I have a mashtun that is twice as wide as it is deep for 5 gallon batches, and has a 1:1 ratio for 10 gallon batches and is also insulated and I'm hoping that I end up with way less temp stratification.

-It's a new system that I'll be using for the first time this weekend so I don't have any existing data to add yet.


Adam

I think you need to allow more time for the temperature to stabilize. I run a Rims system and have had pretty constant readings but I wait for all the wort to circulate for about 15-20 minutes before expecting consistent readings. That said, you may have bad insulation on your MLT or you may be experiencing some channeling. I think a sparge arm might be a good idea.

Manifold, mesh tube, false bottom, or ?

Cheers!

I don't necessary think my MLT needs more insulation. If I don't recirculate I don't drop more than a few degrees over an hour.

I guess I have a second question: If you're doing a protein rest and then want to mash for a fuller body, how would you do that by using a RIMS or direct fire method? I'd imagine by the time you got up to 150+º you'd have spent a long time already in the 130-140 range!

If you want to do a protein rest, do you recommend double infusion? With my current issues, I know I'm going to do that next time.

(I have a false bottom)

I had inconsistent mash temps when I was using a false bottom that was too small for my MT. A probe thermometer in the mash would be all over the place. I have since made two changes and have not had a single issue...a full diameter false bottom (15") from Bobby M at brew hardware and redirecting my recirculation return into a small whirlpool. The whirlpool does not stir the whole bed up by any means, just spins the top 2" of water.