Mash tun/Lauter tun on heat?

[sparkyaber]

OK, so I have been doing all grain for over a year, and want to start doing all ten gallon batches, which are mostly to big to fit into my current 10 gallon Cooler MLT. My cooler has a manifold that works awesome, never a stuck sparge. I have an extra burner laying around, so I figured I would make the step to a SS MLT with a false bottom, or braid, or even a manifold. i guess this would be my question, how are most of you doing it? I am guessing that most with a false bottom will have some scorching when the heat is applied? Do I have to use a pump? (not really what I want to do). Will a manifold work very well in a round SS pot allowing enough stirring to avoid scorching? Same for the braid. I really don't want to ever worry about a stuck sparge. I want it to stay as hands off as possible, with the least amount of moving parts. re: easy!
I thought I could continue the way I am going, mash on heat and then transfer to a different vessel for the lauter.
Any opinions?

 

[SpanishCastleAle]

I use an MLT with a false bottom and apply heat all the time. But I'm mashing on my stovetop so I don't have as much heating power as a propane burner. Never any scorching so far but I don't give it full-on high heat...close to it though.

 

[sparkyaber]

Thanks spanish- what type of of false bottom do you use? A "taller"one, or just a little guy. I can turn the heat down pretty low, so I may be ok.

 

[SpanishCastleAle]

It's a 10g Blichmann Boilermaker so the space under the false bottom is small. There is a small 'build-up' of grain particles on the underside of the false bottom when I direct-fire it but they are the same color as the grain (eg - very light colored for light colored beers). The bottom of the kettle is still shiny stainless.

I sometimes recirculate a quart or so through the valve while heating but usually just stir it. Stirring near the bottom with an upward motion seems to mix it well enough (based on thermometer readings just before/after stirring).

 

[Bobby_M]

I would only direct fire a tun with a false bottom because it keeps the thick mash off the heated surface. However, since you can't really stir enough to exchange liquid between the mash and wort below the FB, you really do want to recirculate (it seems Spanishcastleale has some success however). Moving from a passive cooler mashtun to a direct fire adds quite a bit of task load to your brew day if you don't have really good insulation and/or an automatic heat maintenance system worked out. I'm not trying to discourage you but a 70qt icecube cooler is pretty cheap.

 

[SpanishCastleAle]

Bobby is right. I insulate my VERY thin-walled MLT with a huge beach towel folded over 3x then wrapped around and held in place with one of those super rubberbands (for holding lawn bags on a big trashcan). It's very high-tech. Plus I use about 2 qt of simmering water to maintain/adjust the temp during the long rest.

I typ only direct-fire to reach mash-out so everything is already converted. If I'm step-mashing I almost always do infusions or all-liquid decoctions until ramping up to mash-out.

 

[sparkyaber]

I was looking at the blichman boilermaker as an option, I am assuming you are using the blichman false bottom also? I have done a few batches using my 1 and only 15 gallon pot as the mash tun, kept it on heat, and then transferred as much as would fit into the cooler, started the lauter, let the grain bed settle, and then add the rest of the grain/wort. I had no problem scorching during the mash, just during the boil, and then, still not that much. I have a huge paddle (an actual paddle for canoeing, lacquer sanded off) that really can scoop up the grain from the bottom of the kettle. I stir all the time. I was worried about the dead space under the false bottom not being able to be stirred.