Help with All Grain Brewing - Particularly Mashing

[Jewrican]

The problem: I have a gravity fed keggle setup with a pump that is giving me some troubles when mashing particularly with temps as well as with circulating the wort.

Equipment Detail:

• Keggle
• burner beneath it
• NOT HERMS (no coil inside)
• False bottom (2 gallons of liquid beneath false bottom)
• home made grain bag with bottom sitting right on the false bottom for better filtration
• thermometer JUST above the false bottom reaching 1/3 into keggle
• insulated lid from silver HVAC insulation material

I often do 10 gallon batches (fills more headspace) and a 90 minute mashes just to make SURE it is converted. I am noticing that i am quickly losing temps when mashing which really concerns me. What can I do to hold these temps? I often start up the burner trying to get the temps up throughout the keg, but my concern is that I am denaturing the enzymes by heating them much higher than they should in order to bring the temps up. I feel like this is a poor practice.

Questions:

1. Should I just ignore the fact that I am losing temp and just get my strike right and let it ride since most conversion is done within about 30 -40 minutes?

2. Am I better off just keeping the flame on the mash the whole time but REALLY low?

3. Is my assumption about the heat denaturing the enzymes accurate and a large concern?

4. I have a thermometer at the false bottom but it never seems to show much of a temperature difference throughout the entire mash. It seems like it is insulated by the grains around it in the mash and not giving an accurate reading. How do you get around this. Even stirring it is tough to get a change in temps on the thermometer but the top of the mash tun seems to have cooled off a good bit.

5. What other recommendations do you have.

 

[acidrain]

I have been fighting heat loss with my keggle based MT for too long.
I've tried heating with short bursts from the flame, but even with aggressive stirring, can't keep an even temp.
I've tried using a blanket to wrap it. That worked pretty well, but if I wanted to bump the temp up, I had to remove the blanked so it didn't catch fire.
I've added flame-proof insulation (rockwool), and that works pretty well for insulation, but the fibers were easily torn.
I added a SS sheet metal cover to the insulation, which saves the insulation, but was expensive.
The bottom remains un-insulated, and that's the weak link.
I've added electric RMS, and that helps with the heat, but is prone to scorching if the flow slows for any reason (even with 110v ULWD element).
I've added a stirring mechanism, which works really well at keeping the temp even, but grains are being sucked into the RMS tube, and I'm back to scorching again.

Looking back, I wish I would have just gone with a cooler based MT.
All I can suggest for you is insulate the MT and just accept heat loss.

 

[eastoak]

step up to recirculating your mash. i bought a blichmann mash module and could not be happier with it. the mash is held within a degree of the set point, no problem. i used to have a cooler mash tun and would never go back to that.

 

[Jewrican]

step up to recirculating your mash. i bought a blichmann mash module and could not be happier with it. the mash is held within a degree of the set point, no problem. i used to have a cooler mash tun and would never go back to that.

HOLY EXPENSIVE!! It's nearly $600 bucks? :cross:

I do have a chugger pump and can recirculate my mash. Feel free to elaborate on your recommendations and thanks for the input.

 

[eastoak]

HOLY EXPENSIVE!! Is nearly $600 bucks what you were referring to? :cross:

I do have a chugger pump and can recirculate my mash. Feel free to elaborate on your recommendations and thanks for the input.

yes it is. it was cheaper when i bought it, i want to say $450+ but i can't remember. there are lots of DIY plans and even kits sold online that do the same thing but i don't have the time to do that. if i was to just start wildly speculating on how it could be done for a lot less money this is what i would say: weld a bulkhead on the keggle for the re-circulation return, i use loc line on the inside. you need to have a temperature probe, mine is on the outlet side of the pump. as you re-circulate you would have to turn the burner on and off (manually) as needed. some people think that a keggle would lose heat quickly but that has not been my experience.

 

[smyrnaquince]

Do you get a strange taste from the burlap bag?

 

[Jewrican]

i have never noticed anything from it and the homebrew club in my area all use them. One of the members sells them.

maybe it isnt burlap... hmm.. ill look it up and see. I dont notice a smell or anything from it.

 

[Jewrican]

yeah.. its def not burlap ha ha. Ill have to see what it is.

 

[MichaelBD]

Go for a RIMS. You'll just have a get a chugger pump and make your own sparge arm. There are many sparge arm designs available and they're quite cheap and easy to make.