Check your thermometers!

Today I brewed my 3rd AG batch.

The 1st (Bee Cave Haus) - I was low on my efficiency and the FG was really low 1.006

the 2nd (Bee Cave IPA) - I again was low on my efficieny and the FG (just bottled) was 1.010

Today, I used a new digital water proof thermomter and compared with the previous thermometer I was using, and it was waaaaay off! I haven't done the math, but I figure I was mashing about 10 degrees below what my target was (hence the low efficiency, low FG, and dry beer).

Just a reminder to check your thermometer's accuracy!

Happy brewing to you all this fall

Wow, thats crazy. I have 3: analog, floating, and digital. analog reads 12 degrees +, floating thermo is about 5 degrees off. And digital is perfect, except that the plug is a bit loose...I check all my thermos a week or two ago.

Make sure you have good batteries in your digital. I had a batch right before my digital thermometer's batteries died and I way missed my efficiency due to inaccurate readings. Put in new batteries and everything was good again. BTW: my floating is about 2 degrees off.

Hey guys, I'm looking to buy a digital thermometer. Could you point me in the right direction, or even post some links to thermometers you trust?

I looked around online, googling and checking amazon, and gah, there are way to many to choose from.

Just broke down and ordered one of the Traceable Waterproof Thermometers on Friday.

Traceable Waterproof Thermometer, 91824 - Lab Safety Supply

They seem to be getting good reviews here on HBT.

"Includes a Traceable® certificate that indicates instrument traceability to standards provided by NIST."

r0botluv said:

Hey guys, I'm looking to buy a digital thermometer. Could you point me in the right direction, or even post some links to thermometers you trust?

I looked around online, googling and checking amazon, and gah, there are way to many to choose from.

Click to expand...

Go to your local supermarket, wallmart, target, bedbath and beyond and get a pyrex one Amazon.com: Pyrex Digital Probe Oven Thermometer/ Timer: Kitchen & Dining or anything similar.

AZ_IPA said:

Today I brewed my 3rd AG batch.

The 1st (Bee Cave Haus) - I was low on my efficiency and the FG was really low 1.006

the 2nd (Bee Cave IPA) - I again was low on my efficieny and the FG (just bottled) was 1.010

Today, I used a new digital water proof thermomter and compared with the previous thermometer I was using, and it was waaaaay off! I haven't done the math, but I figure I was mashing about 10 degrees below what my target was (hence the low efficiency, low FG, and dry beer).

Just a reminder to check your thermometer's accuracy!

Happy brewing to you all this fall

Click to expand...

Same happened to me when I started brewing. I now do not trust digital thermometers & only use normal analog ones.

WOW! $80 for a thermo? I have 3 - an analog that I don't trust, a digital and a remote digital. I also have a lab grade adapter for my fluke meter. I'll be running a check on all these before my next brew.

My el cheapo digital from Wal-Mart is pretty accurate. I've never officially checked, but I'd say it cant be more than 1-2 degrees off.

I never trust the dial thermometers that come with fryers and kits. I usually double check with my instant read dial meat thermometers.

I check ALL of my thermo's together at every brewday. It takes no time at all to cold check while you are setting up your gear. Hot checking does take more time but if the thermo is spot on cold then it is rare, I find, that it will be off warm.

mykayel said:

Go to your local supermarket, wallmart, target, bedbath and beyond and get a pyrex one Amazon.com: Pyrex Digital Probe Oven Thermometer/ Timer: Kitchen & Dining or anything similar.

Click to expand...

I have been using this pyrex thermometer for 1 yaer now. Works perfect and cost less than $20 at Bed, Bath & Beyond. Tested 3 times in ice water and boil and it was accurate each time.

If you are just checking them against each other, any temp will do. If you want to know which is right, you will need to use the ice water approach or boil some water.

Linc

HOLY CRAP! My thermo went bad 3 days after my brewday. Check it out:

Therm1: Old (Identical model as Therm2)
Therm2: New

Therm1: reads 68*F in my Fermenter water
Therm2: reads 50*F in my Fermenter water

Thats a 18* difference!!!

Therm1: reads 213*F in boiling water
Therm2: reads 212*F in boiling water

1* difference...WTF

I'm pretty sure that the problem was that i left the thermometer on top of the BBQ as i was boiling my AG and it was out in the sun for about an hour. I then went to use it, all the symbols were lit, even when i turned it off.

It's still kinda shocking that it reads 18+ in cold water and 1+ in hot.

Like AZ_IPA said: "Check your thermometers" before brew day!

I have killed two of the Tar-jay Tru-Temps (one got moisture in it) and the other fell from it's perch and shattered the display, and one floating thermometer (read my Brew Day Disaster thread for details....

I am using a basic analog therm for now until I can sack up and get this Here...

Here's a little thermometer study I did about a year ago:

https://www.homebrewtalk.com/f11/thermometers-thermometers-thermometers-39360/

Looks like you can still get the same Good Cook on fleabay:
Good Cook Instant Read Meat Poultry Digital Thermometer - eBay (item 120308518633 end time Oct-21-08 11:29:18 PDT)

i didn't know what you guys meant by "ice water method" so i did a little googling and for those of you also wondering
Ice water method = A bowl of ice water should have a temp of about 32 degrees
Boiling water method = boiling water should have a temp of about 212
Also adjust for altitude = -2 degrees per 1000 feet of elevation for boiling water

I use lab thermometers myself, I have a red spirit and a mercury thermometer that I use. I prefer the mercury thermo for mashing because it reads the temp much faster. They're not certified, but still accurate to within half a celcius.

Funny I should see you around here Tentacles.

I also use lab grade thermometers, red alcohol type. The only pain is constantly having to convert between celcius and fahrenheit. It reads about 97C at boiling, which is no more than a degree or so off.

The +18 to +1 is really odd. Normally liquid filled thermometers will have relatively linear scales. There arn't any air bubbles in there are there?

CHansen6 said:

The +18 to +1 is really odd. Normally liquid filled thermometers will have relatively linear scales. There arn't any air bubbles in there are there?

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Im using a digital/probe thermometer from Wal-Mart.

I like to check mine during the boil. Nice and easy.

I use an inexpensive taylor meat thermometer that has wired probe. It's within half a degree accurate when I compared it to my lab's thermocouple. $15 on fleabay. Or $20-25 locally.

I bought this one. http://www.crateandbarrel.com/family.aspx?c=3036&f=27296

I was missing my mash temps so badly that I finally tested my thermometers with some ice water and boiling water. They were both bought from home brew shops for home brewing and they were both off around 10 degrees.

So...I got this one: Amazon.com: CDN Proaccurate Stainless Digital Thermometer: Kitchen & Dining

It was accurate to within a degree on both ice water and boiling water and can be calibrated.

I guess I spoke too soon. I just brewed a batch yesterday and after see this post I remembered to test my thermostat and it was ~12-16 degrees high on the low side. It showed my body temp was 112! Boiling temp was good though. Looks like you really cant trust these things. Good thing I had a backup....

i have 2 wired digital thermometers that are both off bad. 1 was from the net and it was good then it went bad then it was good then it was bad again today it was 157 in our house. i got mad and chucked it. then i got a taylor from target which doesn't even read anymore. it worked for 1 time. then i got 3 analog thermometers which i check all the time since i use them for work. i need to find a good 1 that i can throw in the mash tun and not have to worry if it gets wet and its accurate.