Mash cap for reducing headspace in SS Kettle MT

[Hannabrew]

I recently upgraded to a 15G SS MT and am looking for a mash cap for not only LoDo reasons but also to reduce my headspace and retain heat better when recirculating.

Ideally I'd like to have a recirulation port in it as well as potentially a thermowell (though that is not a requirement as I already have an unused port in the side of the kettle I could use).

The ID of the MT is 17.5 (yes its wide) and the lid that came with it is flat but I would need to cut it and I'm not sure how I would go about doing that. My 15G Spike BK lid is 16" and works fits fairly decent but I'm not sure I want to mess with that, especially since it's not a perfect fit.

Another option I'm considering based on some threads I just read on the german brewing forum is using a 2 in Styrofoam circle cut to size and covered in 3m 3361 SS Tape (with silicon used to adhere it securely). This would have the added benefit of being a better insulator than a SS lid however I'm unsure of the side effects of using these materials. I'm also not sure how well putting a bulkhead through Styrofoam will work but I'm sure it can be done.


Is anybody else putting recirculation ports in their caps? Also, regardless of which option I go with, I'm thinking I'd like to have that silicon lining around the edge so that I don't have to rely on the "floating" aspect of it. What are people using for that silicon lining and how does it stay on?

 

[Smellyglove]

You can get some thin silicone tubing as the lining. Slice it open in the length direction and just stick it onto the edge around the cap/lid. Done it, works like a charm.

Maybe you can place the lid upside down on the vessel, strike around it with a marker, and use a tool, like dremel or such and cut it just inside of the marking?

I'd go for recirculation port in that lid, this way it follows your mash/grist-size. You can add a sprinklerhead on the "inside" so the wort will spread, but beneath the wort-surface of your mash.

 

[Hannabrew]

You can get some thin silicone tubing as the lining. Slice it open in the length direction and just stick it onto the edge around the cap/lid. Done it, works like a charm.

Maybe you can place the lid upside down on the vessel, strike around it with a marker, and use a tool, like dremel or such and cut it just inside of the marking?

I'd go for recirculation port in that lid, this way it follows your mash/grist-size. You can add a sprinklerhead on the "inside" so the wort will spread, but beneath the wort-surface of your mash.

1/2 inch silicon like the kind I use for my pump?

 

[Smellyglove]

1/2 inch silicon like the kind I use for my pump?

I used 6mm. But. 1/2" works too, but you can go way smaller.

 

[cyberbackpacker]

If your MLT's opening matches the ID (I say this because on most keggle MLTs the opening is smaller than the ID), you could always have someone like Jaybird (Norcal brewing) whip you up a solid piece of stainless with a handle and a recirc return port fitting of your choosing. If it is a reduced opening like on a keggle, you could have someone like Jaybird whip up the same thing, except with hinges.

Basically, you want someone to make you essentially a false bottom with solid stock instead of perforated.

 

[Hannabrew]

If your MLT's opening matches the ID (I say this because on most keggle MLTs the opening is smaller than the ID), you could always have someone like Jaybird (Norcal brewing) whip you up a solid piece of stainless with a handle and a recirc return port fitting of your choosing. If it is a reduced opening like on a keggle, you could have someone like Jaybird whip up the same thing, except with hinges.

Basically, you want someone to make you essentially a false bottom with solid stock instead of perforated.

Good idea, I'll reach out to him and see what it would cost.

 

[day_trippr]

Unlike a false bottom, you don't want the mash cap to sink.
I expect a flat piece of stainless sheet isn't going to just lay atop the mash for long.

I've been thinking about how to fabricate caps for my 20g Blichmann G1 kettles, which are ~ 17.5" ID.
I reckon I'd start with something like 20ga SS sheet with a tig-welded rim a couple of inches tall, with the all-up outside diameter able to fit freely inside the kettles - and recognizing the kettles have a flat-ish arc section at the vertical seam that would need accommodation.

If I get that far, then I'd experiment with a through-fitting for attaching a line for recirculation and sparging (I prefer to fly sparge). I'd start with a simple elbow and see what happens. I might need to split the recirculation between a couple of through-ports and have them point in opposite directions to keep the whole thing from trying to spin.

And then there's seeing if my autosparge will play nice with the control arm riding on a raft

Cheers!

 

[Hannabrew]

Unlike a false bottom, you don't want the mash cap to sink.
I expect a flat piece of stainless sheet isn't going to just lay atop the mash for long.

I've been thinking about how to fabricate caps for my 20g Blichmann G1 kettles, which are ~ 17.5" ID.
I reckon I'd start with something like 20ga SS sheet with a tig-welded rim a couple of inches tall, with the all-up outside diameter able to fit freely inside the kettles - and recognizing the kettles have a flat-ish arc section at the vertical seam that would need accommodation.

If I get that far, then I'd experiment with a through-fitting for attaching a line for recirculation and sparging (I prefer to fly sparge). I'd start with a simple elbow and see what happens. I might need to split the recirculation between a couple of through-ports and have them point in opposite directions to keep the whole thing from trying to spin.

And then there's seeing if my autosparge will play nice with the control arm riding on a raft

Cheers!

It would definitely sink without something to hold it up. That's why I would make it slightly smaller than the inner diameter and add a silicone gasket so I could set it wherever I wanted it. Especially necessary if I'm going to put a port on there

 

[day_trippr]

Got ya. Thought about that route, but I'm so enamored with my autosparge I want to try to at least not preclude it by using a gasket...

Cheers!

 

[Hannabrew]

I was just planning on using a locline underneath the recirculation port on the lid.