Best Thermometer

I just finished my third all grain batch and I am sure I have thermometer calibration issues. I bought a $12 dollar dial thermometer for use in my batch/sparge water and used my existing dial thermometer for the mash. I used boiling water at 200F (I am at 6300 ft) to calibrate afterward and determined the mash thermometer was 10F too hot. The next batch the new thermometer was 8F too hot using the same boiling water method. So far this seems to be confirmed with dry finishing beer.

The question is what is best for a mash thermometer? A digital one with a probe from Target? An old school mercury (or whatever they use) glass one?

I am a noob, but I am really trying to conquer my mash temp before advancing my skills and can't see how a dial thermometer is worth very much for that purpose.

Buy a thermapen. Issue solved.

I had to Google a thermapen to see what it is. Certainly a pricey thermometer. Does anyone have a more economical solution?

That company makes a variety of products. I got one from them for under $25 shipped. It's basically the same as a thermapen, except it reads in 6s versus 3, has a smaller temp range (but it's still fine for brewing/baking and such), and is slightly less accurate. It's also short a couple features, but I don't care. I'm very pleased with it.

The thermapen might be pricey, but in my mind, knowing that your themometer is accurate is priceless.

For the mash, an old fashioned floating thermo works wonders.

I picked up this one the other day for $15. I have not had a chance to use yet, but am brewing tomorrow.

Just an FYI. I decided to test it out by boiling water. It read 201.9 F in boiling water and I am at ~5700 feet so it is within 1 degree. From room temperature it took approximately 13 seconds for the reading to stabilize. It isn't as fast as those hi dollar thermometers but for $15 I am very happy.

Dahoov said:

I picked up this one the other day for $15. I have not had a chance to use yet, but am brewing tomorrow.

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I like the digital grill/barbeque thermometer I picked up from Lowes for $20 -25. I'm betting it is accurate to 1 or 2 deg F. It had a lead so you can let it dangle in the mash or whatever. Plus you can cook chicken to absolute perfection on the grill.

Octavius said:

I like the digital grill/barbeque thermometer I picked up from Lowes for $20 -25. I'm betting it is accurate to 1 or 2 deg F. It had a lead so you can let it dangle in the mash or whatever. Plus you can cook chicken to absolute perfection on the grill.

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What he said. I am looking forward to being able to see my mash temp without taking the lid off my tun.

Just keep in mind that a good reading at boiling and freezing does not guarantee a good reading at mash temps. The thermapen is certified. I collected (wasted my money) on plenty of 10-$20 units before I got my thermapen. Only one of the cheapos was even close at mash temps.

lschiavo said:

Just keep in mind that a good reading at boiling and freezing does not guarantee a good reading at mash temps. The thermapen is certified. I collected (wasted my money) on plenty of 10-$20 units before I got my thermapen. Only one of the cheapos was even close at mash temps.

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That's a good point.
I would think, though, that a grilling thermometer would need to be half-way accurate otherwise folks would get food poisoning. Or is that wishful thinking on my part - that the manufacturer ran some sort of calibration?
Cheers!

I would hope some calibration would be done but it was hard to tell IMO. Although the one of my collection that was closest was a grilling thermo. Accurite iirc.

Generally for mashing we are trying to hit a number within a 4 degree range. Doing that with a thermometer that is even a few degrees off will not produce the beer you planned. IMO the thermapen gives great accuracy for a reasonable cost.

lschiavo said:

I would hope some calibration would be done but it was hard to tell IMO. Although the one of my collection that was closest was a grilling thermo. Accurite iirc.

Generally for mashing we are trying to hit a number within a 4 degree range. Doing that with a thermometer that is even a few degrees off will not produce the beer you planned. IMO the thermapen gives great accuracy for a reasonable cost.

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Fair enough.

Right now I can't tell the difference between mashing at 150 and 154 so I can't justify the expense to my sugar momma. I will however put it on my X-Mas list.

Dahoov said:

Just an FYI. I decided to test it out by boiling water. It read 201.9 F in boiling water and I am at ~5700 feet so it is within 1 degree. From room temperature it took approximately 13 seconds for the reading to stabilize. It isn't as fast as those hi dollar thermometers but for $15 I am very happy.

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Dahoov said:

What he said. I am looking forward to being able to see my mash temp without taking the lid off my tun.

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At the very least, waterproof the lead per Bobby's instructions. https://www.homebrewtalk.com/f11/remote-probe-thermometer-wort-proofing-26905/
The walmart digital thermometer will not like the wort enviroment if you don't waterproof it. I found out the hard way the first time I used it for brewing. It was reading my temps ok in the boil kettle, but went haywire in my mash tun. I had to bake the lead at 350f to remove all moisture from it, and then seal it with Bobby's method and now it works again. FYI, one o-ring is enough to seal it.

lschiavo said:

Buy a thermapen. Issue solved.

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Agreed. They are expensive but mine does triple duty (brewing, in the kitchen, at the grill.)

Dahoov said:

... I can't justify the expense to my sugar momma. I will however put it on my X-Mas list.

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That's how I got mine.

If you want to check your thermometer, you can get a glass bulb type lab thermometer from ebay for under $10. With no electronics to drift and no moving parts to get sticky, these thermometers are very reliable (thermal expansion of a fluid does not change over time). We had a glass bulb thermometer at work we used as a master calibrator for our other thermometers. We sent it off to a NIST cal lab once a year. In 20+ years it always came back dead on every time.

I recently saw one on ebay that had a temp range of 75F-172F. Perfect for checking your brewing thermometer at mash temps.

Snowhere said:

At the very least, waterproof the lead per Bobby's instructions. https://www.homebrewtalk.com/f11/remote-probe-thermometer-wort-proofing-26905/
The walmart digital thermometer will not like the wort enviroment if you don't waterproof it. I found out the hard way the first time I used it for brewing. It was reading my temps ok in the boil kettle, but went haywire in my mash tun. I had to bake the lead at 350f to remove all moisture from it, and then seal it with Bobby's method and now it works again. FYI, one o-ring is enough to seal it.

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+1 I wrecked my oven thermometer probe 'cause I assumed it was waterproof.

spagyric said:

+1 I wrecked my oven thermometer probe 'cause I assumed it was waterproof.

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+2. NOW I see this thread heheh. Oh well I just bought the old school probe. That will work for now.

Have you tried Taylor precision thermometers? They only cost around $9 to $20 dollars. I got one and I have no trouble calibrating it. Looks like you need a little help calibrating. Try to go over this calibration guide. It might help.

+1 on the Thermapen. It is amazing. It's a real man's thermometer.

Judge said:

Agreed. They are expensive but mine does triple duty (brewing, in the kitchen, at the grill.)

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Same here. It's amazing for the grill. I used to dry out my chicken way too much on the grill and be disappointed. Since using the Thermapen, I've been taking them off at the right temps and having juicy chicken. ]

I just wish the probe was a little longer. I have to use my old dial thermo for taking the temp of my starter wort because I can't get the probe down into my flask.

I've easily spent $93 so far on crappy testing equipment, and still have no clue how hot my mash actually is. I have calibrated at boiling....way off, and using ambient temps in my house near my thermostat.

I may have to make this purchase.

I got a Thermapen a while ago, and now my steaks are also always spot on, how everybody likes theirs

I bought two lab thermometers off of ebay. I calibrated them and one was a bit off, so even if you have the bulb type, you need to know if they are accurate. I eventually ended up with two identical digital stick types that can be adjusted. This way, I have one that lives in the mash tun and one that I use for the strike and sparge water. Seems to work well for me and total investment for all 4 was less than 50 bucks.