Need advice on thermometers for Rubbermaid 10 gallon coolers

Hi, I'm fairly new to all-grain. I have 10 gallon Rubbermaid coolers for my MLT and HLT. I'd like to add thermometers, so I don't have to open the lids to check temp.

My MLT has a domed false bottom that is already tricky to get in and out under the bulkhead, and I don't want to complicate that when I do this.

Should I get threaded weldless thermometers like those on bargainfittings.com, drill through the cooler, waterproof with o-rings, and plan on removing the MLT thermometer when taking the false bottom in and out?

Is there a better way to do through the wall thermometers that will still reach near the center of the mash without interfering with insertion/removal of the false bottom?

Should I drop a probe in from the top on a lead? Is there a best practice for that?

Thank you all for any help.

My advice would be you don't need one.


Pre heat your tun, hit your mash temp, close the lid...go away for 60 minutes.

The cooler will hold your temp very well for 60 minutes...and extremely well for the 15-20 minutes that actually matter.

Xpertskir said:

My advice would be you don't need one.


Pre heat your tun, hit your mash temp, close the lid...go away for 60 minutes.

The cooler will hold your temp very well for 60 minutes...and extremely well for the 15-20 minutes that actually matter.

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This would also be my advice for the mash tun. I occasionally check the temp after 60 minutes and the most it has dropped is 1 degree.

As for the HLT, drill a hole in the lid and stick the probe down through it.

Agree 100%. My Rubbermaid cooler usually doesn't even drop 1 degree over a 60 minute mash. Unless you really, really want one, you don't need it. Spend the money on something else!

bja said:

This would also be my advice for the mash tun. I occasionally check the temp after 60 minutes and the most it has dropped is 1 degree.

As for the HLT, drill a hole in the lid and stick the probe down through it.

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I'm probably over-reacting to noob problems. First time, I got my mash water up about 10 degrees higher than strike temp, as recommended, but got impatient waiting for temp to drop, and added cold water. Naturally, mash temp didn't stay where it needed to be.

Second time, I pre-heated the MLT and was patient on temp--no temp problems in the MLT. But my HLT was just holding sparge water too long, I guess, and it fell below temp. Maybe because it took so long to recirc until the wort ran clear.

The reason I'm interested in thermometers is so I can know if there is a problem *before* the point when I need things to be at a certain temp, especially in the HLT.

Trippel-A said:

Hi, I'm fairly new to all-grain. I have 10 gallon Rubbermaid coolers for my MLT and HLT. I'd like to add thermometers, so I don't have to open the lids to check temp.

My MLT has a domed false bottom that is already tricky to get in and out under the bulkhead, and I don't want to complicate that when I do this.

Should I get threaded weldless thermometers like those on bargainfittings.com, drill through the cooler, waterproof with o-rings, and plan on removing the MLT thermometer when taking the false bottom in and out?

Is there a better way to do through the wall thermometers that will still reach near the center of the mash without interfering with insertion/removal of the false bottom?

Should I drop a probe in from the top on a lead? Is there a best practice for that?

Thank you all for any help.

Click to expand...

I just drop in the probe from my stc 1000 and close 'er up. The wire is plenty thin enough to allow the lid to close well. As the others have said, its not really necessary with a single infusion mash. I still prefer to have it in there for the peace of mind though.

Trippel-A said:

I'm probably over-reacting to noob problems. First time, I got my mash water up about 10 degrees higher than strike temp, as recommended, but got impatient waiting for temp to drop, and added cold water. Naturally, mash temp didn't stay where it needed to be.

Click to expand...

Use a brewing software that will tell you exactly what temp your strike water needs to be. Then there's no waiting for temp to drop or adding cold water.

Second time, I pre-heated the MLT and was patient on temp--no temp problems in the MLT. But my HLT was just holding sparge water too long, I guess, and it fell below temp. Maybe because it took so long to recirc until the wort ran clear.

Click to expand...

Take the money you're going to spend on thermometers and get another burner and pot for the HLT. You then have full control over the strike and sparge temps. IMO using a cooler for a HLT is asking for problems.

bja said:

Use a brewing software that will tell you exactly what temp your strike water needs to be. Then there's no waiting for temp to drop or adding cold water.

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I used Brew Smith 2 for the first time, and I couldn't find a place to say whether I'm preheating the MLT or not. I'm going to continue to aim high and patiently wait for my water to hit strike temp until I've got more experience under my belt.

bja said:

Take the money you're going to spend on thermometers and get another burner and pot for the HLT. You then have full control over the strike and sparge temps. IMO using a cooler for a HLT is asking for problems.

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If I could get another burner and a pot for the same price as a thermometer I'd be a happy camper. Major cost differential there.

Bobby_M said:

http://www.youtube.com/watch?v=lXRj9CVwIfY

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Thanks, Bobby, very helpful!

I have the extended bulkhead with compression fitting from brewhardware.com on my 10 gallon igloo. it works great with zero leaks.

Gumbys_Brew said:

I have the extended bulkhead with compression fitting from brewhardware.com on my 10 gallon igloo. it works great with zero leaks.

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Thanks, Gumbys!

Trippel-A said:

I used Brew Smith 2 for the first time, and I couldn't find a place to say whether I'm preheating the MLT or not. I'm going to continue to aim high and patiently wait for my water to hit strike temp until I've got more experience under my belt.

Click to expand...

The software adjusts for it. You just enter the temperature of the mash tun along with the temperature of the grain. No need to preheat it.

If I could get another burner and a pot for the same price as a thermometer I'd be a happy camper. Major cost differential there.

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I guess that depends on your definition of major cost differential.

bja said:

The software adjusts for it. You just enter the temperature of the mash tun along with the temperature of the grain. No need to preheat it.

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Thanks. I'll look for that next time. I've used it once so far.

bja said:

I guess that depends on your definition of major cost differential.

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The cheapest way I know to get another burner and a pot is to get a turkey fryer on sale (which is what I brew in now) for somewhere between $80-100. I won't use it for anything else. I will also need a pump, so that I can fly sparge from the HLT turkey fryer on the ground into the MLT (whereas now I can just put my Rubbermaid cooler up on bricks on top of a patio table).

The thermometer I'm planning to get is this one, which I can use for other things, like cooking. http://www.brewhardware.com/thermometers-71/135-cdn-remote-probe It is $20. I'll also want parts for a thermowell, which will cost an additional $21. The thermometer option is therefore less than half the additional turkey fryer option, and I'll have purchased something that I'll use for other things.

Another option, I suppose, would be to spend hundreds on the brew kettle and burner that I really want, and use my existing turkey fryer as the HLT, but I'm not going to make that investment until I've gotten good enough and brew all-grain frequently enough to make it worthwhile.

Trippel-A said:

The cheapest way I know to get another burner and a pot is to get a turkey fryer on sale (which is what I brew in now) for somewhere between $80-100.

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You can find them for $40-$50 if you look.

http://www.lowes.com/pd_406086-1337...L=?Ns=p_product_qty_sales_dollar|1&facetInfo=

Cheap good burner. You can even go cheaper with this http://www.lowes.com/pd_406413-1337...L=?Ns=p_product_qty_sales_dollar|1&facetInfo=

A round beverage cooler can be a very effective and much easier to manage hot liquor back than a non-automated kettle. The key is to ensure that your sparge water is around 180F going into the cooler. The sparge water temperature will stabilize in the low 170s and drop to around 168F by the time that it hits the mash/lauter tun when continuous sparging. Any overshoot temperature-wise can be handled via small cold water additions just before you get ready to sparge.

I agree with going in hot. In fact, if the cooler was sitting in the cold garage, even 190F isn't out of the question. As mentioned, it's way easier to cool it off with some cold water than it is to dump it all back into a kettle to add heat.