Issue maintaining temp on a directly heated keggle mash tun

[Jablestein]

Hey all,

I've done 4-5 AG brews now but one of the things I consistently have problems with is maintaining proper temperature while mashing. I'm using a Keggle that's been fitted with spout and thermometer as my mashtun along with a standard bayou classic outdoor propane burner. I wanted to reach out to others who might be using similar equipment to see what process or techniques they're using to combat these issues.

My general process...
-Fill Mashtun with 4 gallons of water - (I pretty much always do 4 gallons regardless of the grain bill. However it's been brought to my attention that I should be paying more attention to how much grain i'm adding and then adding a proper amount of water to the mash to promote better efficiency and attenuation)
-Heat Mash Tun directly with burner until water begins to boil - (My concept of boiling has always been "bubbling water" but I've noticed that waiting for visible bubbling is generally putting me way over the 150-160 mark on my temps...so perhaps I should be heating this to a specific temperature instead)
-Add in grain and stir - Around this time I'm kicking the heat down low but maintaining it. Again though, with the direct heat I'm still having an issue keeping a constant temperature.
-Continue stirring every 10-15 minutes

I'm taking all my temps with a digital thermometer. I have an analog thermometer built into the mashtun but it always seems to be lower than the digital readings I take and it also takes much longer to reflect the current temperature, making it tougher to trust. (I need to calibrate the analog thermometer on the keggle...i've neglected to do so yet).

I'm beginning to wonder if I should treat the keggle like I would a cooler conversion mash tun and just heat the water separately, add it to the keggle and then mash in the grain WITHOUT heat, and maybe seal the top to maintain constant temp over the hourlong period before I begin batch sparging. Any thoughts or suggestions from fellow brewers using similar equipment?

 

[Pratzie]

Calibrate calibrate calibrate.

Can't stress that enough, especially if ur having issues maintaining temp. Its crucial for all grain.

Ive seen some people wrap insulation around their kettle AFTER they turn the flame off. U can also put a lid on the top to keep the heat inside as well.

Your going to lose heat either way, but alot of that will depend on ambient temperatures. I'd def check it every fifteen or so minutes with both thermometers, stirring before you check. then add the heat from the burner to help maintain. I'd also stir during those burns as well to keep the temp as consistent as possible thru the mash.

 

[simcoe26]

Hey all,

I've done 4-5 AG brews now but one of the things I consistently have problems with is maintaining proper temperature while mashing. I'm using a Keggle that's been fitted with spout and thermometer as my mashtun along with a standard bayou classic outdoor propane burner. I wanted to reach out to others who might be using similar equipment to see what process or techniques they're using to combat these issues.

My general process...
-Fill Mashtun with 4 gallons of water - (I pretty much always do 4 gallons regardless of the grain bill. However it's been brought to my attention that I should be paying more attention to how much grain i'm adding and then adding a proper amount of water to the mash to promote better efficiency and attenuation)
-Heat Mash Tun directly with burner until water begins to boil - (My concept of boiling has always been "bubbling water" but I've noticed that waiting for visible bubbling is generally putting me way over the 150-160 mark on my temps...so perhaps I should be heating this to a specific temperature instead)
-Add in grain and stir - Around this time I'm kicking the heat down low but maintaining it. Again though, with the direct heat I'm still having an issue keeping a constant temperature.
-Continue stirring every 10-15 minutes

I'm taking all my temps with a digital thermometer. I have an analog thermometer built into the mashtun but it always seems to be lower than the digital readings I take and it also takes much longer to reflect the current temperature, making it tougher to trust. (I need to calibrate the analog thermometer on the keggle...i've neglected to do so yet).

I'm beginning to wonder if I should treat the keggle like I would a cooler conversion mash tun and just heat the water separately, add it to the keggle and then mash in the grain WITHOUT heat, and maybe seal the top to maintain constant temp over the hourlong period before I begin batch sparging. Any thoughts or suggestions from fellow brewers using similar equipment?

I use a direct heat mash tun as well (with a keggle and a bayou classic burner)and all those things you think you should be doing you should start doing on your next batch. Keep doing the direct fire for the strike water but after doughing in kill the heat. Use 1-1.5 qt of water per pound of grain to mash with and if you want to mash at 152 bring your water about 10 degrees over that target.

Also what i do to keep the heat instead of keeping a small flame on the mash the whole time is I made a wrap around my tun with reflextix. You can get it at home depot or Lowes in the insulation area and it is about 30 bucks for the large roll. I also got some insulation tape and just wrapped the reflectix around about 4 time taped it off and I still had enough to make a lid out of. I lose about 1-2 degrees in an hour mash. The only downside to the reflectix is once you mash in and slide it over your tun you cannot use a flame. But the 1-2 degree loss should be sufficient enough you won't have to.

 

[grathan]

I find that the metal rim under my keggle holds enough heat to sustain mash temps. If you can afford it. I would get a ThermaPen. If not, calibrate your thermometers and get a feel for how far they are off and also how long they take to adjust.

 

[Jablestein]

Thanks so much for the responses! I'll definitely look into the insulation you've suggested. I was actually quite surprised how well the keggle itself held the heat (but I guess it was a keg and meant to try and maintain temps so it makes more sense than I give it credit for). Actually, after I killed the flame the temp continued to rise in the mash.

Definitely looking at getting a ThermaPen, a buddy has suggested them. I hate my current digital and analog thermometers. Definitely need to calibrate the analog though.

 

[simcoe26]

Thanks so much for the responses! I'll definitely look into the insulation you've suggested. I was actually quite surprised how well the keggle itself held the heat (but I guess it was a keg and meant to try and maintain temps so it makes more sense than I give it credit for). Actually, after I killed the flame the temp continued to rise in the mash.

Definitely looking at getting a ThermaPen, a buddy has suggested them. I hate my current digital and analog thermometers. Definitely need to calibrate the analog though.

You should always factor in about a 2 degree rise in temp after flame off. The number you really care about is loss of degrees over an hour

 

[jhay_x7]

This is what I would do if I were you. Buy a roll of Reflectix and make an insulation wrap for your mash tun and also use some of the leftovers to make a "lid". I cut a horseshoe shape out of the bottom of mine so it will fit over my keggle fittings when I slip it over the keg.

Take it off the mash tun, heat your water and then take a spray bottle of water and hit the outside bottom of the keg with the water to cool down the outside of the keg and then slip the Reflectix over the keg. If you dont cool the bottom part of the keg down a little, it will melt the Reflectix. This should keep your mash temp steady for 90 minutes.

What I do is fill my mash tun with the correct amount of water, place my Reflectix over the keggle and then place a bucket heater in the water attached to a temp controller the night before. When I wake up in the morning, I am ready to dough in!