How do you measure mash temperature?

[Martin G]

Always feel like I am doing a mental average of the mash temp. I have got a thermopen and find no matter how much I mix the mash the temp can be 1-2C different at different points in the mash. Is there a 'correct' method?

[boingy]

I think the best way is to keep probing around until you hit the exact target temperature, measured to one decimal place. Then you post a piccy of it on here and the rest of us all look with envy at your ability to exactly hit 66.0 degrees every time.

In reality there is always going to be a temperature differential across the mash. I give it a good stir when I mash in. Leave it for 5 minutes then stir well again and measure the temperature in the middle, a few inches under the surface. My process is consistent enough that I usually get within a degree of my target and I rarely bother adjusting it from there. And I don't know how accurate the thermometer is anyway.

[Bert]

I am no expert but I do in a few places and if it's roughly were I want it to be +/- 2 degrees then that's good enough for me

[jaroporter]

i must be one of the few people who worries about the mash gaining temperature. i stir for ages to get stable readings, as the temperature plummets below target, and end up roughly above or on target by the end. fück knows what the actual temperature during is but beer it does make and i always hit expected FGs. i guess i kinda mash "high" or "low" rather than at a certain temperature.

[phill71]

I too catch myself sticking the thermapen in and out, sampling various parts of the mash. I suppose it's to be expected that the outer edges will be slightly cooler, so I've come to accept that now, and I'm comfortable if the bulk (ie the centre) is showing on or very close to the target temp.

[fego]

A RIMS or HERMS set up will sort out any mash temp issues. Otherwise, its best to measure and test a lot and take an average and when you get good results, just repeat what you did/measured....

[Dr. Dextrin]

I have a thermometer probe strapped to my wooden stirring spoon. I stir, then leave the spoon in the centre of the MT and put the lid on. Leave 5 mins, stir again, put lid on. If the temperature is way off after 10 minutes I may then think about correcting it, but that's pretty rare.

[Martin G]

I think the best way is to keep probing around until you hit the exact temperature, measured to one decimal place. Then you post a piccy of it on here and the rest of us all look with envy at your ability to exactly hit 66.0 degrees every time.

Te hee

Interesting range of approaches.

[AnthonyUK]

Re-circ BIAB
I find this is accurate enough for me.

[Martin G]

That recirculating BIAB, I guess it is a bit like a HERMS? do you have a heater in the system somewhere?

Re-circ BIAB
I find this is accurate enough for me.

[AnthonyUK]

Apart from the big stainless thing?

At the moment the PID switches the boiler but this is inefficient although surprisingly accurate. I have a spare kettle and may try a copper heat exchanger at some point so more like a traditional HERMS but I don't know if I can be bothered with the additional complexity at the moment.

[pobrien20]

Do you recycle for all mash time or only when temp goes out of tolerance range, i.e. goes up or down? Why is the PID inefficient?

I'm also BIAB and was thinking of going along the lines of STC/PID controlling the 2 elements & solar pump recycling into mash as you have.

(As for going down the Arduino route of automated step mashes, programmable brews, multiple probes, relays, ... MUST STOP COMPLICATING THINGS, JUST FOR GADGETS SAKE ...)

[AnthonyUK]

Hi,
The PID isn't inefficient but I'm guessing heating the full volume in the boiler rather than a smaller volume like in a HERMS system.
I recycle at the beginning to get to the set mash temp as soon as possible and sometimes at the end to clear to wort if I can.

[boingy]

Like all things in brewing you can make it a simple or as complicated as you like. If you mix grain with water and you know the temperature and quantity of each then you end up with a mixture at a known temperature. Pre-heat the MT or allow for it's temperature and you make beer.

But you do have less gadgets to play with that way...

[nala]

A RIMS or HERMS set up will sort out any mash temp issues. Otherwise, its best to measure and test a lot and take an average and when you get good results, just repeat what you did/measured....

Theoreticaly...yes...in practice far from it
I am developing a HERMS system of a kind, I started off with the tradition cooler mash tun, tried all sorts of false bottoms to enable the wort to recirculate at sufficient rate to keep the temperature correct at the various mash stages.
To date, have not managed it, I am using a HEX and pump capable of 20 litres per minute, the trials I have done without the grain suggest that the system is capable of recirculating the strike water and achieving the various ramp temperatures and times, however when the grain is introduced to do a brew the flow rate through the grain is not so good and consequently the mash temperatures are all over the place up to 6 degrees lower. I run the thermocouple at a higher temperature to allow for this but until I can improve the wort recirculation better I have failed. Those HERMS users who do not check the grain bed are only kidding themselves that their system is working, ignorance is bliss I suppose !