measuring mash temp?

This might be a silly question... I use a square cooler as my MLT (photo below, ignore the piss logo, it came on the cooler many years ago) so my grain bed is usually fairly deep. I'm in the middle of a mash right now, and I'm curious how deep into the mash should I be measuring the temp? I have a standard thermometer standing in the corner so the bulb is at the very deepest point, and it's reading 156... however when I bring the bulb up to where it's only a couple inches into the mash, it drops down to about 153. My target was 154, so I'm probably a bit high I'm assuming?

I'd say stir it up more. The mash temperature is critical and having some of the grain high and some low will change your results.

I would stir it. It will probably equalize close to 154.

Doesn't your furry brewing buddy have an advice?

The cat does look concerned. Stirring is the best way to get a handle on the average temp of the mash as others have mentioned. Unfortunately, you will lose some heat from the MT when you open the lid to do the stirring. There's no perfect solution to this problem and it is one of the main reasons I switched to a RIMS system. OTOH, your beer will likely come out just fine.

BTW, you have a beautiful cat.

+1, I was surprised how much stirring it takes to even out the grain temp...I used to think that it was just normal for the temp to fluctuate a few degrees around the tun, but on my last couple of batches I stirred "a lot", several minutes I would guess, and to my surprise, much less deviation.

I stir my mash about every 15 minutes which also gives me time to check my mash temp and iodine. Is that a normal frequency.

I noticed that problem as well when I started all grain. I leave the stirring paddle for the boil and use a paint mixer attached to my drill, 30 seconds and it mixes very well.

Scut_Monkey said:

I stir my mash about every 15 minutes which also gives me time to check my mash temp and iodine. Is that a normal frequency.

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I never stir mine once I've mashed in. I know my temp won't drop more than a degree or 2 if I don't open the cooler. Every time you open it to check you lose heat.

Denny said:

I never stir mine once I've mashed in. I know my temp won't drop more than a degree or 2 if I don't open the cooler. Every time you open it to check you lose heat.

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This is entirely true. I simply don't trust my software to be dead on accurate. Granted my cooler drops in temp each time but I figured opening it 3 times during the mash and then a fourth time when it should be finished was not as big a deal. I simply like to know with confidence that I'm hitting my mash temp and getting proper conversion according to iodine testing.

To each his own.... and with good reason.

Scut_Monkey said:

This is entirely true. I simply don't trust my software to be dead on accurate. Granted my cooler drops in temp each time but I figured opening it 3 times during the mash and then a fourth time when it should be finished was not as big a deal. I simply like to know with confidence that I'm hitting my mash temp and getting proper conversion according to iodine testing.

To each his own.... and with good reason.

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I cook BBQ competively and this is just like at a BBQ contest. Newbie BBQ teams want to know why their brisket or ribs or pork never really cook completely and they score poorly. Then you realize that they are opening their cooker every 30 minutes to look at the meat. Duh!

what if you some how incorporated your stirring system into you mash tun like a brewery might do, only smaller.

I could drill a hole just barely big enough for the shaft of the paint stirrer i use to fit through and a smaller one for my temp probe and that way i wouldn't have to open it up to stir or check temp.

or something

you could. But, at the very beginning, in the first 5 minutes or so, stir like it's your job. Stir so that there are NO temperature differences, no matter where you check. Then, cover it and walk away. It'll be fine for the rest of the hour. Trust me on that! I used to worry, and check, and adjust. But I found that once it was stirred so well I thought my arms would break off, that it didn't change even a little bit. I no longer even bother to check it after the first 10 minutes.

YooperBrew said:

you could. But, at the very beginning, in the first 5 minutes or so, stir like it's your job. Stir so that there are NO temperature differences, no matter where you check. Then, cover it and walk away. It'll be fine for the rest of the hour. Trust me on that! I used to worry, and check, and adjust. But I found that once it was stirred so well I thought my arms would break off, that it didn't change even a little bit. I no longer even bother to check it after the first 10 minutes.

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I think I'll start doing this. I really had no idea that's what experienced brewers were doing. I thought checking it 4 times during an hour long mash was normal. I'll try this on my pumpkin batch coming up.

I think I'll start doing this. I really had no idea that's what experienced brewers were doing. I thought checking it 4 times during an hour long mash was normal.

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Well to be fair, I seem to recall that this is what Palmer advocates in How to Brew. I did that on my first couple of AG batches and kept seeing my temps drop, and drop, and drop every time I opened it to stir. Then I figured I'd just put my water in a bit warmer and stir the hell out of it to get it to my target temp, wrap it up in blankets or whatever was handy, and leave it the hell alone. Ever since I took that approach I've seen only 1-2 degree drops in my mashes over an hour+.

Like I said I open the cooler about 3 times during the actual mash and my temp drops about 4 degrees but this is also with a cooler with a ton of headspace compared to my grain bill. I use to do it a lot more but recently I've felt like it was pointless and dumb so I cut it back to what I thought was "normal". I think I would have eventually done away with checking the temp but this helps to confirm this idea and I'll be doing it. Thanks everyone.