Correct temperature, where ?

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walther

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Hi,

I circulate the wort through the grain bed during mash.

Which is most important to keep at the desired temperature, the grain or the circulated wort ?

(I can overshoot the wort temperature, or have too cold a grain bed).

Thank you,
walther
 

mbird

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Why do you circulate your wort during the mash? I circulate at the end of the mash to clarify the wort then sparge with 180f. water. The grain bed never does get that hot, maybe up to 160f. but my efficiency is good and that is the important thing to me.
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Catt22

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IMO, the grain bed temperature should be your target. I use a direct fired RIMS and do a continuous circulation while mashing. My kettle has the typical large dial thermometer with a 4" probe into the mash about 5 inches up from the bottom through the kettle wall. The probe is not quite in the center of the mash, but it's close enough and this is where I monitor the grain bed temperature. I also monitor the returning wort passing through the cpvc manifold above the mash using a continuous reading digital thermometer. When simply holding a steady mash temperature I circulate at about 1-1/2 gpm with the burner on a very low setting. The returning wort should be about 3 F above the target mash temp as there will be some losses along the way down through the mash. I monitor the dial thermometer and as I approach my target temperature I reduce and finally shut off the burner and let it coast. Usually the mash temp will stay very constant and drops only very slowly. As soon as I notice any drop in temp, I re-ignite the burner and adjust the returning wort to a degree or two above the target. Most of the time little or no adjustment is required once you reach the target temp. When ramping up the temps I shoot for 5 or 6 F above the target temp. This allows a reasonable temp gain while avoiding overheating or scorching the wort. The faster you circulate the more heat you can apply while still keeping the return wort only a few degrees above the desired target temp. The tricky part is circulating fast, but not so fast that you stick the mash. I'm installing a vacuum gauge on the kettle output to monitor the pump suction. I want to push the limit on the recirculation rate and needed a way to monitor the suction with more precision. Previously, I simply watched the return flow and made flow rate adjustments more by guessing than anything else. You don't know where the limit is until you exceed it. I've also learned not to overcrush the grain and getting that right took awhile.

So, yes do want to "overshoot" the wort temperature to maintain the grain bed temperature. Patience is required because it will take several minutes at least for adjustments to register on a thermometer monitoring deep in the mash. It takes some time for the heated wort to make it down through the mash at the rates we are pumping. Hence, the need for a reasonably fast pumping rate.
 

Catt22

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Why do you circulate your wort during the mash? I circulate at the end of the mash to clarify the wort then sparge with 180f. water. The grain bed never does get that hot, maybe up to 160f. but my efficiency is good and that is the important thing to me.
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Continuous circulation of the wort on a RIMS type system helps maintain a constant and uniform grain bed temperature. It also allows you to ramp up the temps for step mashing and/or the a mashout. It's not about clarity, but about the mash temperature although clear wort is a nice byproduct. I suppose that the conversion would be more uniform with continuous recirc simply because the liquid portion of the mash would be constantly mixed maybe impoving the enzymatic action.

There are lots of ways to mash and lots of ways to make beer. It really comes down to your personal style. Some of us are gadget types and some aren't. Unfortunately, I'm one of the less fortunate gadget people.
 
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walther

walther

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Thank you for the quick and long! replies :)

What I was thinking about was putting something like an immersion chiller in the grain bed, and circulate worth both thru the grain (~10%) and thru the chiller(~90%), thereby getting a more accurate mash temperature and faster temperature changes ?

I'm a gadget kind of person btw.
walther
 

Catt22

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That could work, but I'm not sure of the gain. You should be getting a good representation of the actual grain bed temperature with the typical dial thermometer inserted into a mid section of the mash. The thing to keep in mind is that it takes awhile to turn over the entire mash volume at the rate we are pumping. ie, six gallons in five minutes or so and you only gain a few degrees with each pass. So long as the returning wort filters down through the grain bed more or less uniformly, then the grain bed temperature will follow. It will lag quite a bit but you can get a feel for it quite easily. Remember the old chinese saying, " a man with two watches never knows what time it is"? Well, it's a lot like that with the grain bed temp. Rather than stirring and probing around in the mash and getting a fairly wide range of temps, just recirc and let the grain bed equalize on its own and use one thoughtfully placed temperature probe or thermometer. Monitoring the wort return temperature is the key IMO as is the fast pumping rate.
 
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