Lets talk about temp readings during the mash

i feel like this topic isnt discussed enough. this is still a big problem for me even after a countless number of brews. i feel like everything runs smoothly including the mash. i still end up with good efficiency and make great beer but during the mash sometimes im not 100% confident i am mashing at the temp of the thermometer. i make sure it is calibrated correctly before i brew and i stir the mash around to get all the wort mixed well before i take my temp readings. i will also use multiple thermometers at times and will get different readings from each one. so my question is how can i get the most accurate temp readings during this critical stage of the brewing process.

Calibrate thermometers to see which are accurate.
I move the thermometer around in the mash to try and get
an average temp. When I am satisfied I close it up and
leave it alone.

i have the same issue. I was thinking about buying one of those digital wireless grill thermometers. It has a probe for the grill and a beeper sized part that clips on your belt and tells the temp so you can go inside and monitor the temp. I was thinking about just throwing that probe in the mash tun and monitoring temp that way so i wouldn't have to open the cooler lid.

You have to be careful with the grill thermometers as if you get any moisture on the wire part it screws with the readings.

Just stir it well when you first dough-in such that you get consistent readings throughout the mash. When stirring try to get the mash from the bottom mixed with the mash on top. Once it sits you'll prob see some temperature gradients both from top to bottom and from the center towards the walls (depending on what you mash in, a stainless pot is quite different than a well-insulated cooler).

Take good notes of your mash temps and what kind of attenuation you get and adjust from there. It seems for me lately that I'm mashing higher and higher just because I'm getting high attenuation (sometimes too high). I think part of the high attenuation is because over time I've gotten better and better at taking care of the yeast where as before I was 'over-compensating' for less-than-stellar yeast health/pitch rates/aeration by mashing too low.

What if your mash temp is lower than desired; can the outcome still be good? I did my first mash last weekend and messed up by pouring in water of 156 deg., which resulted in a 65 min. mash at or around 146 deg. According to the Beersmith software and my OG reading, I had 90% efficiency. How is that possible and/or is that temp. range still ok?

EuBrew said:

You have to be careful with the grill thermometers as if you get any moisture on the wire part it screws with the readings.

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+1....learned this the hard way. Heated my strike water using the grill thermo - everything was fine. Then, I tried to measure my mash temp with it and it wigged out on me. Thankfully, I had a back up.

The key in my mind is consistency. Your mash will ALWAYS develop temperature gradients unless continually agitated, something most of us don't do.

Here's my system:

1)Dough in
2)Mix thoroughly, (I use a paint mixer on a drill).
3)Shut lid and wait 5 minutes.
4)Take mash temp at center of cooler, probe sticking in ~4".

Of course, what my probe reads at 4" down, center of cooler will be different than what it reads at 2" down, edge of cooler. The point is, I follow this procedure EVERY TIME. That means, relative to my other batches, it's consistent. So, while my 153°F on my system might actually equate to someone else reading 151°F, I know what 153°F gets me with MY SYSTEM. After doing a few batches, I know what a 150°F, 153°F, 155°F, 157°F, and 159°F beer all taste like, so I can judge what mash temp I want to hit from there. Again, if I read a recipe that says "mash at 154°F", it might really mean 152°F on my system, depending on how they read their temp vs how I read mine, but 152°F on my system is ALWAYS 152°F, so I can say, "hmmm, this beer is supposed to be neither too malty nor too sweet, which I normally get at more like 152°F, so I think I'll aim for 152°F on my system instead of 154°F.

Make sense?

Waunabeer said:

What if your mash temp is lower than desired; can the outcome still be good? I did my first mash last weekend and messed up by pouring in water of 156 deg., which resulted in a 65 min. mash at or around 146 deg. According to the Beersmith software and my OG reading, I had 90% efficiency. How is that possible and/or is that temp. range still ok?

Click to expand...

If your temp is anywhere between say 145F and 170F you are mashing. Really, some reactions will occur at even lower temps than that. The difference is that lower temps will result in a lower malt more attenuative mash. Higher temps result in the reverse. You will still get conversion at lower temps. It will just change the flavor and body of the beer.

shortyjacobs said:

The key in my mind is consistency. Your mash will ALWAYS develop temperature gradients unless continually agitated, something most of us don't do.

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This really is the crux of the issue. It's all about consistency and what works on your rig. There is no magic bullet so to speak. Unfortunately, there will always be a degree of trial and error. I'm still dialing in my current rig because many of the components are new.

shortyjacobs said:

The key in my mind is consistency.
Make sense?

Click to expand...

I agree that consistency and learning your own rig is key. My own strategy is to trust BeerSmith temperature calculations even above my thermometer once the mash has been mixed.

My first couple batches once I mixed I was never happy I'd get a hot spot reading to high and a clump too low and be opening the lid multiple times to add hot or cold water and trying to get the right temperature and reading. Now I:
1. Use BeerSmith enter my recipe, mash volume and goal mash temperature and allow it to calculate the temperature of my mash water.
2. Dump my water into my tun about 5 degrees above that to preheat the cooler.
3. Once my temperature is at the number BeerSmith gave me add my grains and mix really well to get all the grains wet.
4. Close the lid and leave it alone.

With a calibrated thermometer I figure the calculation BeerSmith gives me must be correct in that amount a of water @ b degrees + amount c of grain @ d degrees = mash temperature and in the past I found the more fiddling I did the harder I made it on myself to hit the temperature correctly.

JJL said:

If your temp is anywhere between say 145F and 170F you are mashing. Really, some reactions will occur at even lower temps than that. The difference is that lower temps will result in a lower malt more attenuative mash. Higher temps result in the reverse. You will still get conversion at lower temps. It will just change the flavor and body of the beer.

Click to expand...

This is good to know. Thank you.

i may have to use the paintmixer on a drill idea and see if that helps. thanks for the responses, as usual i learned something new from you dudes.

Paint mixer works awesome. Many worry about Hot Side Aeration and only run it super slow....I gave up on that and run it fast because I'm impatient, but it works either way .