Mash Tun Temperature Control

[guitarpat]

I had an idea for controlling my mash tun temperature. I'm using a 10 gallon water cooler for my mash tun. Trying to hit the target temperature is a pain. I like the idea of a RIMS system but I don't have the money for it. My idea is, Can I use a copper coil inside my tun and run hot water through it? Kind of like a immersion chiller in reverse. I can re-circulate boiling water and use a temperature controller to cycle the pump. Has anyone tried this?

 

[bitteritdown]

That may work though it might be more trouble than its worth. If you're not also recirculating the mash (in addition to pumping the hot water through the coil) you'll run into hot spots around the coil. You'd have to control two pumps: the mash recirculation pump and the heating water/coil pump. Then there's the question of the temperature of the water in the coil... With enough effort and research it may be possible.

 

[guitarpat]

I figured I would have to stir it often. It would be easier than adding hot and cold water and manually reaching my target temperature.

 

[actionjackson905]

I have been using this calculator for about 2 years using a 10 gal rubber maid orange water cooler. I brew 10 gal batches, and use a 5 gal cooler for 5 gal batches. Works perfectly: http://www.brewheads.com/strike.php Make sure all your inputs are exact, including grain temp. If your brew room temp is room temp, and set your loss to 1. I'm never off my mash +/- .5, and usually bang on.

 

[Hwk-I-St8]

I use brew365.com and my experience matches @actionjackson905. I always preheat my cooler MLT with the hottest tap water I can and dump that just before adding strike water. I'm almost always less than a degree off my target mash temp.

That being said, what you're describing building is just a homemade rims system isn't it? I thought about doing something similar so that I could easily do step mashes, but that's down the road quite a bit.

 

[RocketBrewer]

A method you might find easier is to use a calculator to get your proper strike water amount and temp for your grain bill. Heat you water at least 5 deg hotter than you want and add the proper amount to the mash tun and stir it till it gets down to your calculated temp. Then add and stir in your grains. You should hit your mash temp every time. Just don't let the calculator adjust the temp for equipment mass.

 

[ancientmariner52]

I had an idea for controlling my mash tun temperature. I'm using a 10 gallon water cooler for my mash tun. Trying to hit the target temperature is a pain. I like the idea of a RIMS system but I don't have the money for it. My idea is, Can I use a copper coil inside my tun and run hot water through it? Kind of like a immersion chiller in reverse. I can re-circulate boiling water and use a temperature controller to cycle the pump. Has anyone tried this?

I had a similar idea, using a 1000 watt heat stick. Sort of a heated mash paddle. I have it wired to a foot switch. I start with strike water that I know will come in a few degrees below my target mash temp. I underlet the strike water, watching the HLT sight glass to measure volume. I shut off the water, submerge the heat stick, start stirring and step on the pedal. I never stop stirring or lift the heat element out of the mash while my foot is on the pedal. I have a fixed thermometer in one end of my mash tun, and one hand free to use a handheld digital thermometer. 3 or 4 minutes of stirring and heating and I'm at my target. Shut the lid, throw a couple of furniture blankets over it, and temps hold very well.

I suppose one could add a thermowell and a controller, but I've got nothing better to do while stirring, so I just watch the thermometers.

 

[jalc6927]

Are you opening tun to stir during the mash? If so, this will lose heat.

If not, make sure you close it tightly

 

[SleepyCreekBrews]

Instead of pumping hot water through a copper coil inside the mash tun , you'd be much better off pumping wort through a copper coil immersed in a pot of hot water. (Sort of a mini HERMS) ...but like most of the rest of the crew said, use the right temperature strike water, and you're usually in there +/- a degree of so.

 

[ESBrewer]

Yes, with standard batch size and well insulated tun you should have no trouble keeping the temperature constant enough for 1-1.5 hours, even without circulation. Gradients, decoction etc. could be more challenging but single step infusion should be manageable. With a micro sized batches (what I do) it will be more challenging without heating or circulation (because there is less thermal energy / surface area) and you may need to find a warm place for the insulated tun (an oven). Anyway, it is important that you learn to know your mash tun and recipe. Programs such as Beersmith (in addition to experience) will be valuable when estimating the strike water temperature. If your tun can't hold the temperature you should probably increase insulation and decrease the amount of stirring after the initial stabilization. You really don't need to open & stir the mash too much (if at all) when the water and grains get mixed and a homogenous slurry has formed. At mash-in, it takes some time when the temperature settles, especially if the mash tun is cold. If your tun is almost empty, it may be more difficult to hold the temperature compared to a full mash tun.

 

[jalc6927]

I drilled a hole one size smaller than the thermometer probe and used FG sealant to hold it on place so I don’t have to remove lid to get temp