Thermometer quandry

Kaz · Nov 21, 2012

I do BIAB 5 gallon batches with a full volume mash. I'm almost at my wit's end with monitoring mash temps. I've been using a Polder oven probe thermometer, but if it gets wort or water in it, it becomes wonky and needs to be baked. Then I'll fall back on a UEI thermistor probe thermometer and probe, but, same problem, if it gets moisture in the probe=fail. Then I will use a good old fashioned glass lab thermometer that came with my original brew kit and/or a floating thermometer. My problem is, all of these are different from each other by as much as 5-10 degrees F! So, I never know what temperature I'm mashing at. I would like something that can get down into the grain bed that is almost 10" down in my 10 gallon kettle, and is waterproof, but that doesn't seem to exist? Or, is it not that important to get the temp down there? What is everyone doing to get an accurate mash temp under these conditions? TIA :mug:

AnchorBock · Nov 21, 2012

Kaz said:
I do BIAB 5 gallon batches with a full volume mash. I'm almost at my wit's end with monitoring mash temps. I've been using a Polder oven probe thermometer, but if it gets wort or water in it, it becomes wonky and needs to be baked. Then I'll fall back on a UEI thermistor probe thermometer and probe, but, same problem, if it gets moisture in the probe=fail. Then I will use a good old fashioned glass lab thermometer that came with my original brew kit and/or a floating thermometer. My problem is, all of these are different from each other by as much as 5-10 degrees F! So, I never know what temperature I'm mashing at. I would like something that can get down into the grain bed that is almost 10" down in my 10 gallon kettle, and is waterproof, but that doesn't seem to exist? Or, is it not that important to get the temp down there? What is everyone doing to get an accurate mash temp under these conditions? TIA

If you stir well you don't need to get to the bottom of the kettle to take a mash temp. I have had similar issues and just bought a Thermapen, just something that wasn't worth dealing with anymore and brought too much uncertainty. I found that my lab thermometer was reading about 4 degrees high even thought I calibrated it at 32 in ice water. My dial thermometers were all over the place.

jwalk4 · Nov 21, 2012

Have you tried calibrate them in the same water? That will tell you what thermometers are accurate and which ones are off.

If you are having trouble regulating your mash temps, then the only cure is to stir your mash more often, and more thoroughly.

william_shakes_beer · Nov 21, 2012

I use a thermapen oven thermometer and have sucessfully waterproofed the probe. Here's what you do;

1. Go to petsmart and purchase a length of silicone air line.
2. Go to Lowes electrical department and purchase a 3" length of heat shrink tubing of the appropriate diameter.
3. Go to CVS and purchase a small tube of vasiline lip balm (not chap stick, the squeeze tube)

Squirt a dab of lip balm into one end of the airline and push the metal end of the probe through. Continue working it along until it is just short of the connector and completely sheaths the probe wire.

trim off the probe end of the airline well below the wire connection to the metal sensor. I usually pick a point midway between the bend and the pointed tip.

Slip the heat shrink tubing over the airline, aligning the center of the heat shrink with the end of the airline.

Heat and shrink using a butane lighter or match.

dadshomebrewing · Nov 21, 2012

i bought a digital thermometer, with a remote, like they use for turkey fryers, online at amazon. i think it was from a company called maverick. a little pricey at about $40.00, i think.

it has a temperature alarm for too high, and too low.

put it in the pot when i turn on the water for mash, when it gets to almost the strike temp, the alarm goes off.

i can even put it right down inside the closed igloo cooler i use for the mash, with the lid on. the remote sits right next to me, and i can monitor the exact temp, throughout the whole process.

also has a built in timer.

works great, and i put the remote in my shirt pocket and i can walk around the house, and do other stuff.

william_shakes_beer · Nov 21, 2012

aw. mine doesn't have a wireless. I have to leave it plugged in!!! Was the temp probe waterproofed? if so, How?

a_hard · Nov 24, 2012

I use my great grandmothers candy thermometer. Its accurate to half a degree and so vintage i want to wear skinny jeans and make ironic statements

RM-MN · Nov 24, 2012

Since you are doing BIAB, you don't really need to monitor the mash temperature. Use a strike water temperature based on the amount of water and the temperature and amount of grains you will be using and make sure you hit this temperature. Stir in the grains well and do a quick temperature check to make sure you are at mashing temp, then put the lid on the pot and wrap it all in something insulating (I use a bath towel but blankets or sleeping bags will work even better) and walk away. Your mash temperature won't change more than a couple degrees over the course of an hour and in any case, if you have your grains milled fine for BIAB, conversion will be done in about 20 minutes.

Kaz · Nov 24, 2012

I do check the strike temp and then again after doughing in. I then wrap the whole thing in towels and blankets. Sitting outside in PA in the winter, I sometimes see a temp drop of up to 5 degrees F. Maybe not something to worry about, but at the same time, right now all of my thermometers read different. I would just like to know which one is right. Good point about the finely milled grains being converting sooner, I hadn't thought of that before.

RM-MN · Nov 24, 2012

Sitting outside in PA in the winter, I sometimes see a temp drop of up to 5 degrees F.

I cheat. I do mine indoors.

However, in my defense it was in the teens yesterday with winds of 15 to 25. When I tried to brew outdoors in that temp and wind my turkey fryer couldn't even maintain the temp, let alone trying to raise it to a boil.

revansCAAD8 · Nov 24, 2012

william_shakes_beer said:
I use a thermapen oven thermometer and have sucessfully waterproofed the probe. Here's what you do;

1. Go to petsmart and purchase a length of silicone air line.
2. Go to Lowes electrical department and purchase a 3" length of heat shrink tubing of the appropriate diameter.
3. Go to CVS and purchase a small tube of vasiline lip balm (not chap stick, the squeeze tube)

Squirt a dab of lip balm into one end of the airline and push the metal end of the probe through. Continue working it along until it is just short of the connector and completely sheaths the probe wire.

trim off the probe end of the airline well below the wire connection to the metal sensor. I usually pick a point midway between the bend and the pointed tip.

Slip the heat shrink tubing over the airline, aligning the center of the heat shrink with the end of the airline.

Heat and shrink using a butane lighter or match.

Any pictures that you could share of this?

william_shakes_beer · Nov 26, 2012

revansCAAD8 said:
Any pictures that you could share of this?

I'll get my camera this evening. Are you looking for materials, process, or the finished product?

william_shakes_beer · Nov 27, 2012

revansCAAD8 said:
Any pictures that you could share of this?

does this help?

revansCAAD8 · Nov 29, 2012

Great, thank you for the picture!
I will at least try the heat shrink tubing to help protect it from moisture. Any concerns with the air line cover melting?

Robert
GypsyBrew

william_shakes_beer · Nov 29, 2012

I've used it in several mashes without issues. Once I reach boil I usually pull it out. The heat mostly makes the shrink wrap tighter.

Hackwood · Nov 29, 2012

RM-MN said:
However, in my defense it was in the teens yesterday with winds of 15 to 25. When I tried to brew outdoors in that temp and wind my turkey fryer couldn't even maintain the temp, let alone trying to raise it to a boil.

I live in Phoenix. What does it mean for temps to be in the teens? Hmm. Never heard of that..... :ban:

masskrug · Nov 30, 2012

I feel your pain. I have That exact (ThermoWorks) probed thermometer. After 1 batch it went wacky. I was like WTF?, and THEN I read the directions, "Do not immerse cable in water." Oh? So that half hour or so getting up to boil was bad? I ordered a replacement cable and learned from my mistake.

TAPPAR · Nov 30, 2012

I have two thermometers that are off by about 5 degrees as well. Did we ever figure out how to figure out which one is reading correctly?

I suppose high school science class was a while ago but it would seem to me that ice water might be a bit off of 32 degrees...

FuzzeWuzze · Nov 30, 2012

Use boiling water, and look up online your elevation and calculate your boiling point. Then use that to set your thermometer, should get you close.

sniperd · Nov 30, 2012

I have a little write up about the thermometer I use:

https://www.homebrewtalk.com/f11/best-digital-thermometer-314825/index2.html

Thermoworks has excellent support.

Thermometer quandry

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