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Accurate Mash Temp

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coachtrt65

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I use an igloo cooler that is pre-heated with water for about 20 minutes and then slowly pump water in around 170 while i dough in and stir. What I have found is my mounted temp probe reads around target mash temp but when I vorlauf the last twenty minutes of mash the temp goes up on avg 6 degrees. So, I guess my question is it more important to dough in at correct temp or maintain an average of desired mash temp. Not sure taking temps every ten minutes then do avg is accurate enough?
 

Oginme

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I aim to start the mash at my target temperature. With my new Anvil, I have been able to maintain that temperature, but previously doing full volume BIAB the temperature would drop a couple of degrees. As long as this is consistent and repeatable, it was not an issue. That is the key is to maintain a repeatable process so that you can get the same results with the same procedure and if you make a change, such as in mash temperature, that change will be reflect some difference in the end product.
 

brownni5

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When I mash in a cooler, I usually shoot for the target mash temp (give or take) at the outset. I will insulate and generally don't lose more than a couple degrees F in 60 minutes. Since most conversion is done well before that, it isn't a problem. Chances are, the drinker wouldn't be able to detect a fluctuating mash temp, though minor changes in fermentability may occur.
 

CharlieW

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Ooops, hit the wrong key I guess. I preheat the mast tun with 2 qts water a little above the strike temp. Dump that water and mash in with the water and grain. I am usually dead on temp wise. I stir my mash every 20 min, and take temp and have noticed a 1F drop overall during the mash time.. Maybe a few stirs will equalize the temp throughout the mash? Just my 2 cents.
 
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coachtrt65

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Ooops, hit the wrong key I guess. I preheat the mast tun with 2 qts water a little above the strike temp. Dump that water and mash in with the water and grain. I am usually dead on temp wise. I stir my mash every 20 min, and take temp and have noticed a 1F drop overall during the mash time.. Maybe a few stirs will equalize the temp throughout the mash? Just my 2 cents.
Ok when you mash in do you do it at intended mash or strike temp? If strike, is it calculated for you?
 

RPh_Guy

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I suggest this process:
  • Use a calculator to determine your target strike temperature.
  • Heat your strike water several degrees above the target strike temperature.
  • Add the water to your cooler.
  • Let it stabilize for 5-10 minutes.
  • Adjust downward with ice if needed.
  • Dough in by slowly stirring in the grain.
Additional insulation never hurts. I used extra blankets and towels around my cooler, especially in the winter when it's friggin cold.

Cheers
 

MikeCo

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Most of the conversion occurs earlier in the mash than at the end, so it is important to dough in and get the correct target mash temperature and keep it stable for the first 30-45 minutes. Using a calculator with the right inputs makes this easy. If you are vorlaufing with hotter water and increasing the temperature a little at the end, I would not worry too much about that.

I'm curious about your strike temperature of 170; it seems high to me. For 5.5-gallon moderate gravity batches and mash temps of 154 or so, I heat my water to 159 or 160. My grains are generally at room temperature. I'm using a stainless kettle (BIAB), not a cooler. Does the strike water at 170 result in mash temperatures in the same range for you?
 

RPh_Guy

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Vorlauf means to take wort from the mash tun drain and put it back in the top of the mash tun (i.e. recirculation) to help clarify the wort that comes out. .... The returned wort won't be any hotter than what's already in the mash tun.

It doesn't make any sense that the temperature would increase during the course of the mash unless heat is being applied, and it certainly wouldn't increase from vourlaufing. The temperature will normally decrease over time, and any time you manipulate the hot wort.
If the temperature appears to be passively increasing then probably the mash wasn't stirred enough and there are pockets of heat.

Troubleshooting:
  1. Is the thermometer calibrated (by you, recently)?
  2. Are you stirring during the mash? How often, how long, and with what?
  3. Can you provide an example of your strike water calculation? (Grain temp, water volume, target mash temp, strike temp)
  4. What temperature is the water you're using to pre-heat?
 

CharlieW

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Ok when you mash in do you do it at intended mash or strike temp? If strike, is it calculated for you?
Sorry for the late reply. I mash in using the strike temp. As RPh Guy said, use the calculator to determine the strike temp and follow the rest of his directions.
MikeCo.. My strike temp is about 170F and after mashing in I end up at about 154F pretty consistently.. Maybe the cooler vs stainless steel?
 

RPh_Guy

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Strike temp depends on the temperature of the grain and the volume of strike water vs the amount of grain. ... The target temperature also matters of course.

Someone doing a full volume mash may only need to strike at 155-160°F but someone who's sparging and has less water in the mash will need higher, maybe 160-170°F or so.
 

eric19312

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I use an igloo cooler that is pre-heated with water for about 20 minutes and then slowly pump water in around 170 while i dough in and stir. What I have found is my mounted temp probe reads around target mash temp but when I vorlauf the last twenty minutes of mash the temp goes up on avg 6 degrees. So, I guess my question is it more important to dough in at correct temp or maintain an average of desired mash temp. Not sure taking temps every ten minutes then do avg is accurate enough?

This sounds like you are probably not mixing the mash well enough. Unless you are somehow adding heat (boiling water infustions, RIMS, HERMS) during the mash it is impossible for your mash temp to be hotter at the end of the mash than it was at the beginning. How is your temp probe monuted? If your thermometer is mounted half way up the cooler side and you see temps on that start to rise once you start vorlaufing that means you are pulling some pretty hot wort out of the bottom and adding it to the top of the mash. For this wort to make your temp go up by 6F -- assuming the thermometer is in the middle of the mash -- I am thinking the wort you are pulling out from the bottom could be much higher than the middle of the mash.

That is a pretty extreme temperature variation. I was kinda prepared to say RDWHAHB on this question but I'd want to reduce that temperature variation as you could in theory have pockets of too hot mash reaching temperatures that would denature your enzymes before they got a chance to convert the wort and other pockets where the mash isn't even reaching gelatization temperature and not even releasing the starches into the wort to be converted.

I'd suggest better stirring at dough in and repeating the stirring once, about mid way through the mash. Keep the cooler well insulated between stirrings. By better stirring I mean like for 5 minutes in a 10 gallon cooler with a decent mash paddle. Not just stirring until the dough balls are all broken up but really get rid of the hot and cold spots in the mash. For the mid way stir you can go a little faster as you want to avoid too much heat loss. You can add some boiling water when you do the mid way stir to keep temps or just dont worry about losing a few degrees.
 

WeHeavy

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Are you by any chance using 2 different thermometers?
I've chased my tail in the past trying to figure out what was going on, when the problem was both thermometers where off. One was high the other low.
You can check it by putting your thermometer in ice water and it should read 32 and then boiling water it should read 212 adjusted for altitude.
 
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