Measuring temperature for mashing

[sebbb]

Hi Folks,

I've been having problem in deciding when it's the right time to start mashing for the following reason.

When water is been heated to reached the desired mashing temperature, I always end up with a lower or higher mashing temperature after pouring all the grain in the pot.

This is because my (mercury) thermometer portrays a different temperature when positioned in different areas and heights. So it's hard to determine the real overall temperature as it portrays higher values at the bottom and lower ones at the top of the liquid volume.

For instance, today I was brewing a stout with desired mashing temp of 68C. I decided to stop heating water when it measured 71.5C. However, after pouring all the grains I ended up with a measured temp of 66C.

I used an alluminium pot of 19L capacity.

Any recommendations on the matter?

Seb

 

[OG-wan Kenobi]

If your cold heat it up if your hot keep stirring until you come down to your desired temp

 

[GoeHaarden]

This is because my (mercury) thermometer

Well, there's your problem...

Might be easier if you invest in a better thermometer. The thermoworks Dot is just as accurate as their thermopen for a fraction of the price. It's only slightly (inconsequentially so) slower. Plus thermoworks has a lot of coupon codes and sales where you can get them for around ~$30.

https://www.thermoworks.com/DOT

 

[Smellyglove]

It has nothing to do with what kind of thermometer. It's just how an unstirred or un-circulated mash works. It's colder on top, and warmer at the bottom, colder at the sides and warmer in the middle. Just stick it in there if you're not happy with the result stick it in somewhere else until you're "overall" happy with what you're reading.

Just make sure you stir it good to even out the temps, it can take more effort that you would think. And stick in in there and see what it reads, write it down, and go for it, unless it's way-way off.

 

[balrog]

One must stir, as has been said.
I stir as I approach strike T°, and history shows I must stop about 0.3° below desired strike, giving me time to turn off propane burner, delicately and carefully set aside my digital thermometer, remember not to grab the now-volcanic pot handles bare handed, and set pot on table. The cast iron burner continues to impart heat during that time.

Then I dough in, put on lid, wrap reflectrix around pot, wait 2min, stir and measure temp by sweeping temp probe hither and thither.

 

[Smellyglove]

One must stir, as has been said.
I stir as I approach strike T°, and history shows I must stop about 0.3° below desired strike, giving me time to turn off propane burner, delicately and carefully set aside my digital thermometer, remember not to grab the now-volcanic pot handles bare handed, and set pot on table. The cast iron burner continues to impart heat during that time.

Then I dough in, put on lid, wrap reflectrix around pot, wait 2min, stir and measure temp by sweeping temp probe hither and thither.

I meant continuously stirred. Since a mash left alone without any movement will lose temps at the outer sides and the top faster than "in the middle". Just stick your thermometer in there and if you're not happy with the reading stick it somewhere else until you're happy.

 

[JohnSand]

I aim for the middle of the mash range, and don't worry if I'm a couple of degrees off. I have been quite high or low, but some heating or ice cubes adjusts it. Relax, don't worry, you'll make beer.

 

[balrog]

I aim for the middle of the mash range, and don't worry if I'm a couple of degrees off. I have been quite high or low, but some heating or ice cubes adjusts it. Relax, don't worry, you'll make beer.

This. +/-2° I won't even think about. Take notes, see if I have correlation to ambient temp or procedure, and adjust strike temp accordingly next time.

 

[sebbb]

Hey guys, thanks for your answers.

Would you generally stop heating just right befote the target Ti is reached, or rather right above it?

 

[JohnSand]

Just below target. The kettle will be hotter than the water, and continue to warm it slightly.

 

[balrog]

Are you measuring grain temp and using a strike temp calc?
It's one of those things where you measure or presume room temp grain temp, calc the strike volume in qt/gal/L, see where it says you should heat strike, then mix and get a difference. Use that next time to see if you can fine tune your setup strike/doughin/mash temp situation.