regulating temp for 5gal kettle stovetop mash?

[rhys333]

I just did a partial mash with 5.5 lbs of grains in 1.5 gal water (going with the 1qt per lb rule of thumb), and had some trouble pinning down temperture. I found it to be a tad stiff and would be tempted to add another quart next time to free up the grains in an attempt to even out the temp. I used a mesh bag to hold the grains, and noticed temp variations of 5 degrees depending where I tested (e.g.: middle of grains, edge, or in the water outside the bag). The instructions I had called for a 1 hour mash at 151 - 155, so a 5 deg variation was a bit frustrating... didn't know whether to boost the heat or leave it alone. I ended up wrapping the kettle with a large towel to insulate and stabilize, with 3 short bursts of heat added during the hour. Seemed to work out, but might be dumb luck.

Is there a tried and tested procedure for ztovetop mashing? Should I insulate and heat as described, or drop I the grains, lid it and just walk away for an hour?

 

[mdreyer93]

I typically follow deathbrewer's suggestion in his stovetop partial mash stickie and wrap my pot in a towel and even put an old pillow on top. I keep a bit of boiling water and cold water on hand for adjusting temps if I have to. Typically, I'll only do that if I'm 4-5 degrees off what I want. Don't go crazy checking temps because each time you remove the lid you let out a lot of heat. I usually mash in and wait at least 10 minutes before measuring. If that's good then I'll check the temp again 20-30 minutes later. I never direct heat the mash. Whatever works for you though, sounds like it went ok.

 

[rhys333]

I waited 15 mins before checking (lid on, wrapped in towel), but i got different readings depending where in the mash i tested. Maybe i juat need to go with it...

 

[firestem4]

I had the same thoughts rhys333. I did a lower temp mash for my steam beer 2 days ago, 148 degrees. It lost a few degrees, especially depending on where I probed with the the thermometer. (I am not surprised by that, many variables in play) But it made it a little hard to tell what my mash temp was overall. I think next time I'll keep a little hot water on hand like mdreyer said.

edit: I also wrapped my kettle in two blankets. I do think it helped with the heat loss although I may try some type of insulating fabric next time. Maybe a winter jacket! Hehe

 

[unionrdr]

After 12 or 15 partial mashes now,I'm noticing some things on thermal efficiency in mashing. The physical amount of mash (water & grains)'s thermal efficiency is directly proportionate to the physical size of the mash vessel. for example,my stout had some 4.3lbs of grains mashed in 1.5 gallons of water in my 5 gallon BK/MT. the temp went down from 156F to 142F over the course of the one hour mash. Now,if I'd have mashed in the 3 gallon kettle,it would've held temp.
5-6lbs of grains in 2 gallons of water in that 5 gallon BK/MT holds temp,even gaining 1 degree more often as not. So I'm seeing a direct relationship with mash vessel size & mash volume as relates to thermal efficiency.
By the way,I heat my mash water with the cake cooling rack in the bottom of the kettle with the nylon grain bag in it wrapped around the lip of said kettle. Floating thermometer suspended in it lashed to the kettle handle with a noose of twist ties. When it gets up to the mash temp I want,I dump in the grains & stir out dough balls & get them wetted evenly & quickly as possible.
Then I wrap it up in my quilted thinsulate lined winter hunting coat tightly to hold the heat in. I set the kettle on the inside back of the coat with two pot holders under it. Pull the hood over the top of the kettle,wrap the sides of the coat around it,& tie them tightly with the sleeves.

 

[rhys333]

After 12 or 15 partial mashes now,I'm noticing some things on thermal efficiency in mashing. The physical amount of mash (water & grains)'s thermal efficiency is directly proportionate to the physical size of the mash vessel. for example,my stout had some 4.3lbs of grains mashed in 1.5 gallons of water in my 5 gallon BK/MT. the temp went down from 156F to 142F over the course of the one hour mash. Now,if I'd have mashed in the 3 gallon kettle,it would've held temp.

I pondered this as well when I was starting the last mash. Had about 5 lbs grains and went with my bigger 5 gal pot and 1 qt water per lb grains. Next time I'll increase the grains to fill more room in the pot (rather have more fresh grain than dme anyway). Also, increase the water to about 1.25 qt/lb grains... I think a slightly looser mash will help with even heat transfer.

 

[unionrdr]

Yeah,5-6lbs of grain in 2 gallons of water in a 5 gallon kettle works well for holding heat in when wrapped up in my quilted winter hunting coat. It actually gains 1 degree over the 1 hour mash. But say I was doing 4lbs of grain in 1.5 gallons of water,then a 3 gallon kettle would be better for holding the heat in.

 

[rhys333]

Yeah,5-6lbs of grain in 2 gallons of water in a 5 gallon kettle works well for holding heat in when wrapped up in my quilted winter hunting coat. It actually gains 1 degree over the 1 hour mash. But say I was doing 4lbs of grain in 1.5 gallons of water,then a 3 gallon kettle would be better for holding the heat in.

Thanks, i'll make note of this for future batches

 

[freisste]

If your pot can fit in the oven, turn it on the lowest setting and turn off before you put the mash pot in. Holds temp great.

I know people have good luck insulating, but insulation can only get so good. If you can match ambient temp to mash temp, you will not lose any heat. No temperature gradient = no heat flow.

 

[unionrdr]

It def seems like it'll save some frustrations with mash qualities as relates to the body & flavor of the finished product. Mash ton physical volume does seem to have a lot to do with mash volume itself.