Mash caps source

[mongoose33]

@Gravitysucks posted this in the boil kettle condenser thread, but it immediately struck me as part of the solution to figuring out how to do mash caps in round containers.

https://www.webstaurantstore.com/vi...ement-lid-for-40-qt-stock-pot/473SSCOVR9.html

The price is fair, though shipping is about just as much, and they have sizes of lids 10 5/8, 11 1/2, 12 3/8, 14, 15, 18 5/8 and 20, all in inches.

I'm using a 5-gallon stockpot lid in my 10-gallon kettle mash tun as a mash cap, and it's not perfect, covering probably....85 percent of the surface? With one of these, one could trim the lip off if that would work and it would fit.

I've just bought a couple of used 20.5 kettles that have lids, but I want a tight-fitting mash cap for it. It's supposed to be 18.75 inches in diameter; I think I could use one of those 18 5/8" lids with the lip cut off, and it would be darned near perfect.

Anyway, for anyone looking for a way to do this...

 

[sheikyerbouti]

Does it have to be stainless? I've been thinking about making one and thought of using plastic. This way, it won't suck of the heat and be light enough not to squash the grain.

 

[mongoose33]

Does it have to be stainless? I've been thinking about making one and thought of using plastic. This way, it won't suck of the heat and be light enough not to squash the grain.

Assuming nothing leaches out of it, that would work. I've used the plastic lid from a 5-gallon bucket as a mash cap.

The issue for me has been in finding a cap that almost perfectly covers the mash and leaves virtually no space on the edge exposed to the atmosphere.

The plastic lid from a bucket covers most, but not all of the surface area inside my kettle. This just occurred to me now, but I wonder if one could get a plastic lid from a 55-gallon barrel (or similar) and cut that down to the perfect size.

There was a discussion on the LODO site about someone fabricating stainless mash caps, it didn't go far as I recall. The problem was that you could get flat stock in stainless but that there needs to be a rim around it that allows it to float. Creating that is difficult.

That's what was so interesting to me about the site above: lots of different diameters and if one could find the right size, then cutting off the flange that prevents it from falling into the pot would allow it to float.

FWIW, here was my attempt to get a mash cap to fit my igloo cooler; I wrapped the foamboard with saran wrap because I wasn't 100 percent certain that the foam was food-safe.

 

[mabrungard]

I used material from a yoga mat as a mash cap. That material can be cut to any shape needed. I did have to glue some stiffeners to the back of the cap.

 

[beernutz]

I use aluminum foil since my mash tun is an Igloo cube. Seems to work pretty well and is recyclable.

 

[mongoose33]

I use aluminum foil since my mash tun is an Igloo cube. Seems to work pretty well and is recyclable.

The reason I didn't use aluminum foil or otherwise is it contributes to Fenton reactions, which create staling compounds.

 

[Schlenkerla]

I plan to use hollow 20mm polypropylene balls... lots of them....and they hold in heat very well.

On a 14"x14" mash tun I need 367.
On my HLT/BK I need 273.

I bought a 1000 for $75. I could double layer them too.

http://eccllc.us/features/

I'm doing this since I stir with a mash paddle. They will next like a hexagonal close pack.

http://butane.chem.uiuc.edu/pshapley/GenChem2/C2/1.html
https://www.e-education.psu.edu/matse81/node/2134

 

[day_trippr]

I've been under the impression that the effectivity of a mash cap is dictated by the amount of surface area it actually contacts. If that's true I doubt a few inch thick layer of spheres is going to be that effective. Where the balls make actual contact with the wort, yes, and perhaps that's as much as half the total surface area. But where they don't the wort is exposed to the elements, so to speak.

Contrast that with, say, a round shallow cake pan that just fits inside the kettle and is positioned in full contact with the wort. There's little surface area exposed to air hence the effectivity should be close to optimal...

Cheers!

 

[Schlenkerla]

I've been under the impression that the effectivity of a mash cap is dictated by the amount of surface area it actually contacts. If that's true I doubt a few inch thick layer of spheres is going to be that effective. Where the balls make actual contact with the wort, yes, and perhaps that's as much as half the total surface area. But where they don't the wort is exposed to the elements, so to speak.

Contrast that with, say, a round shallow cake pan that just fits inside the kettle and is positioned in full contact with the wort. There's little surface area exposed to air hence the effectivity should be close to optimal...

Cheers!

Yeah, I know.... 91% coverage is better than nothing.

They nest at a hex 91% is the minimum coverage if you can get hex shape with a ball in the center of the hex. More balls is moderately better or worse depending on the gap outside the hex.

Square igloo cooker 14x14 with 1.5" corner radii. Not even a 11" will fit well. No squircle baking pans.

I use a mash paddle. No pump.

My igloo looses heat bad so this does two things act as a cover and retains some heat.

I used them for plating so I know the heat retention and chemistry impact.

I'm trying them. Not sure to oxygen benefit, definitely helps with heat.

Flying Dog Drewery uses them for this application. So I'll wing it...

 

[day_trippr]

Ah, well, hollow but airtight shapes are great insulators, so if that's mostly what you are going for, vaya con Dios
I'm surprised the Igloo is so poor at holding heat - I thought they were supposed to be better than the comparable Rubbermaid (btw, how weird is that brand name? )

CHeers!

 

[Schlenkerla]

Ah, well, hollow but airtight shapes are great insulators, so if that's mostly what you are going for, vaya con Dios
I'm surprised the Igloo is so poor at holding heat - I thought they were supposed to be better than the comparable Rubbermaid (btw, how weird is that brand name? )

CHeers!

It's the partly the size and utilization. How full is the mash tun. Stirring with a mash paddle is major source of heat loss. So I flip back and forth with 5 gallon and 12 gallon mash tuns...

Come to think of it the 2, gallon I have is rarely used...LOL.

I had often wondered what extraction rate you'd get with 1qrt per pound in strike water with no stirring for 60 minutes.

Rubbermaid is so you to don't start a second family with the hired help.

 

[day_trippr]

[...]Rubbermaid is so you to don't start a second family with the hired help.

Hilarious!

 

[Schlenkerla]

Got my balls from Fedex today. - LOL

I thought a 1000 balls would be in a large box. Damn was I was wrong. 8x8x6 box. It's plenty to cover my BK, MLT and HLT.

I washed them and now doing a boil for cleaning purposes. They were really dusty.

The second picture has a mash paddle standing in the middle.

This picture has about a 4" layer of balls.

So at 12:30 temp was 210F. Thirty minutes later it's 198. Heat off. Should be good at mash temps.

 

[aeviaanah]

Check out my mash cap build. I get 100% coverage and a vacuum tight seal. I also use a keggle with a smaller opening then surface area of mash

View attachment 607706

View attachment 607708

 

[lump42]

I've just bought a couple of used 20.5 kettles that have lids, but I want a tight-fitting mash cap for it. It's supposed to be 18.75 inches in diameter; I think I could use one of those 18 5/8" lids with the lip cut off, and it would be darned near perfect.

if you're looking for a tighter fit, you might be able to split some high temp tubing and use it as a seal. I've seen it done in some of the diy stainless fermenter threads. Just a thought.

 

[Schlenkerla]

Check out my mash cap build. I get 100% coverage and a vacuum tight seal. I also use a keggle with a smaller opening then surface area of mash

View attachment 607706

View attachment 607708

Wow wow wii, it's a very nice!

 

[Iseneye]

if you're looking for a tighter fit, you might be able to split some high temp tubing and use it as a seal. I've seen it done in some of the diy stainless fermenter threads. Just a thought.

Yep that is what I did. I had a stainless lid thingee but it had a bit of clearance around my mash pot and wouldn't float so got silicon tubing, cut it down the middle, then created a makeshift gasket.

 

[Schlenkerla]

Here's one layer balls in my HLT/BK. Holds temps really good.

 

[Schlenkerla]

My square mash tun....

 

[mongoose33]

Check out my mash cap build. I get 100% coverage and a vacuum tight seal. I also use a keggle with a smaller opening then surface area of mash

View attachment 607706

View attachment 607708

The system won't show this to me. Don't know why. I get a "You do not have permission to view this page or perform this action" error.

 

[Schlenkerla]

The system won't show this to me. Don't know why. I get a "You do not have permission to view this page or perform this action" error.

You got logged out by the system. Close and reopen.

There might be HBT server issues.

The above square cooler picture wouldn't show up, but the other round one did. Not sure why, considering i uploaded that one first.

 

[day_trippr]

I can't see @aeviaanah's two pics in Chrome (or IE or FF) on my peecee but I could see them on the HBT Android app.
And I like it!
I'm assuming that's a slab of thick silicone, where does one obtain such material?

Cheers!

 

[Die_Beerery]

Can someone repost? I can’t see them either. If silicone that’s a bad choice. Silicone is super o2 permeable.

 

[Schlenkerla]

Can someone repost? I can’t see them either. If silicone that’s a bad choice. Silicone is super o2 permeable.

How permeable is super?

Asked and answered...

These are the water vapor transmission rates of silicone.

The second is oxygen transmission rates.

 

[mongoose33]

I still can't see the attachments. Rebooted HBT, the PC, nothing.

So silicone is O2 permeable. How thick is the above silicone, and how does that compare to whatever is in the pics I cannot see?

 

[day_trippr]

First time I ever had to drag pics from the HBT app to the deskside machine...

The silicone rubber sheet looks to be 1/4" thick from here. I highly doubt there'd be significant transmission of O2 in the course of a mash.

Pricing a large enough piece of FDA compliant silicone rubber sheet to cut out caps for my 20g (~ 17-5/8" ID) mlt and hlt is staggering. Is there a cheaper source of FDA compliant material?

Cheers!

 

[RPh_Guy]

I want something cheap and easy.
Too much to ask?

 

[milldoggy]

These are not too much

http://rover.ebay.com/rover/1/711-5...0001&campid=5338413729&icep_item=192220292838

 

[day_trippr]

I don't see FDA or "food grade" compliance anywhere in that ad.

McMaster-Carr has 24" square 1/4" thick high temp food grade for $155

Cheers!

 

[mongoose33]

I don't see FDA or "food grade" compliance anywhere in that ad.

McMaster-Carr has 24" square 1/4" thick high temp food grade for $155

Cheers!

Which puts me back at....stainless steel kettle lids.

 

[Franktalk]

How about this stuff? You can cut it to size.
https://www.usplastic.com/catalog/i...MIu8ewjfn53wIViorICh36OgC-EAQYBCABEgJpAPD_BwE

 

[RPh_Guy]

The shipping is killer. Think I might have to look around locally.

 

[Schlenkerla]

I've wondered if you could find a good thin food grade sheet material, then line your mash tun with the material. Then back fill it with a can of great stuff foam. Then wrap it closed and shrink wrap it with a heat gun.

I suppose you could buy sheets to of insulin foam core and cut it to size and then wrap it with saran or foil.

 

[milldoggy]

FDA silicone https://www.equalseal.com/product-p/fdasilicone.htm

60 for a 24x24 x1/8
20 for a 24x24 x 1/32

 

[day_trippr]

And $124 for 24x24x1/4
Pretty sure the OP's pics show 1/4" thick rubber.
Still pricey - but cheaper than McMaster-Carr...

Cheers!

 

[day_trippr]

Check out my mash cap build. I get 100% coverage and a vacuum tight seal. I also use a keggle with a smaller opening then surface area of mash[...]

What does the grain bed look like post-lauter? Is there a big hole drilled in the middle from that return line?

Cheers!

 

[milldoggy]

And $124 for 24x24x1/4
Pretty sure the OP's pics show 1/4" thick rubber.
Still pricey - but cheaper than McMaster-Carr...

Cheers!

If it seals and keeps out the 02, does size matter(insert bevis meme)

 

[day_trippr]

I suppose that depends on the supporting structure making up for the increased "floppiness" as the thickness decreases. The ultimate goal is to seal to the kettle wall and the thick material used should do that well as shown. Otoh, taken to the extreme where the material was paper thin, one could expect it wouldn't lay as flat on the surface as well as thicker material for the same unsupported length. And it wouldn't have as much resistance to deformation so how well it would hold to the kettle wall might be compromised.

But the armatures shown in the OP's pics could be widened out to compensate - you could take them to with a 1/4" or so of the diameter unless the kettle was deformed - so that'd be an option...

Cheers!

 

[milldoggy]

Wonder if a stainless pizza pan would work with the thin silicone.

Norpro 5673 15.5in S/s Pizza Pan https://www.amazon.com/dp/B000SSXG1E/?tag=skimlinks_replacement-20

 

[mongoose33]

Wonder if a stainless pizza pan would work with the thin silicone.

Norpro 5673 15.5in S/s Pizza Pan https://www.amazon.com/dp/B000SSXG1E/?tag=skimlinks_replacement-20

Not sure how well that would work. It it were flat, with a lip, perhaps; as it is, there's a pretty large area that is "dished" and that would allow air in there.

Something like this may be better:

https://www.amazon.com/dp/B004FRYC7G/?tag=skimlinks_replacement-20