Keggle Mash Tun

[Oktoberfest]

Converting a keg for a mash tun and have a few questions. I think I understand the purpose of the false bottom (Keep grains off bottom so they don't scorch), but still a little unclear as to what the dip tube accomplishes. I am assuming this is used directly with a pump to move the wort to boil kettle. If that is the case, it would seem there would be liquid at the bottom that never really circulates through the grains. How High should this false bottom sit from the bottom of the keg to avoid scorching?

Batch sparging - since I have more room to sparge, is it acceptable to sparge the entire mash at once or should I still be splitting it up into 2 sparges? I can see running a continuous flow of sparge water in and stirring until I get my total pre-boil volume, but not sure if that is good practice from an efficiency standpoint.

Maintaining mash temp - What is the best way to maintain mash temp in keggle? Should I keep a constant flame on bottom and stir and adjust accordingly?

Thanks for any info.

[tlael]

The false bottom really doesn't have to be too high to prevent scorching. That has a lot to do with your later question of regulating mash temp though...
To regulate mash temp effectively, you'll need to employ some kind of recirculating method. Most common are HERMS and RIMS and some people, myself included, recirculate and direct fire the mash tun as you touched on. That is just what it sounds like... applying a direct flame to the mash tun while constantly recirculating the wort.
Recirculation of the wort is key in all three methods. Where the temperature is measured can (and should) be different for each method to properly regulate temp without scorching the wort.

Stirring a direct fire mash without recirculation is pretty demanding and can be very difficult to maintain even temp.
Wrapping the finished keg/mash tun in Reflectix (search @ Lowes) is paramount... this stuff will help the vessel hold temp... without it you'll have a very long, uphill battle.

As for sparging... batch or fly (continuous) both work well. But, there really isn't a need to split the batches like you said since you have the room.

[spiderwrangler]

I can see running a continuous flow of sparge water in and stirring until I get my total pre-boil volume, but not sure if that is good practice from an efficiency standpoint.
.

If I'm understanding this right, you are asking about running water in at the same time you draining off and stirring it? If so, not something you want to do. If you are going to fly sparge (and really, why bother ) the idea is to run an even amount of water down through the grains so it will rinse evenly. If you are batching, you would drain off, fill with sparge water and stir, then drain off again.

[Oktoberfest]

awesome. thnx for the replies guys. Sends me in a research direction. Still unsure about the dip tubes role. Again, guessing that it has a direct tie to pumping wort to boil.

[tlael]

Again, guessing that it has a direct tie to pumping wort to boil.

Pumping wort in general... both for recirculation and getting it to the kettle.

The diptube's job is to get all the wort you possibly could from the mash tun thus increasing efficiency.
In a RIMS or HERMS you could drain from the bottom center of the mash tun, but this is pretty hard if you're direct firing. You'd scorch the hell out of the wort in the drain tube if you direct fired with a bottom drain.

[Oktoberfest]

ok, that makes sense. Looks like lengthy debates on RIMS vs HERMS. Any recommendations on modding a keg? Things you would do differently. Things that worked or didn't work. Things that would have made the mash process much smoother. I only want to do this once and I've learned in the past to gather info 1st beforehand. Thanks for all your help guys.

[tlael]

ok, that makes sense. Looks like lengthy debates on RIMS vs HERMS. Any recommendations on modding a keg? Things you would do differently. Things that worked or didn't work. Things that would have made the mash process much smoother. I only want to do this once and I've learned in the past to gather info 1st beforehand. Thanks for all your help guys.

Making a mash tun is pretty simple once you've decided on the whole Direct Fired/RIMS/HERMS thing.
Just plan your drain so you can get all the liquid (with a dip tube) and make a return that is high enough to clear any size grain bed. And.... wrap with Reflextix.

Just make sure when you're making a mash tun or kettle out of a keg to watch the placement of the fittings on the lower half of the keg so that they do not sit directly above one of the lower skirt vent holes. Most kegs have four of these placed 90 degrees apart. If you have a fitting above one of these and decide to direct fire at some point, you will heat your fittings up pretty damned quickly.

Clear as mud?

[TastyMcD]

ok, that makes sense. Looks like lengthy debates on RIMS vs HERMS. Any recommendations on modding a keg? Things you would do differently. Things that worked or didn't work. Things that would have made the mash process much smoother. I only want to do this once and I've learned in the past to gather info 1st beforehand. Thanks for all your help guys.

I've posted this picture of my mashtun before on this forum. It's a modified Heineken keg. The unique thing is that it has a drain in the bottom. It's the only mashtun I've ever had and I've been using it about 14 years.
Tasty