adding insulation to kettle lid

hey guys and gals.

Im trying to figure a way to insulate the lid of my 10 gal brew kettle so I can use it as a mash tun. Ive seen mention of using foam to fill up headspace, but cant imagine how to do that without ending up with the wrong kind of foam in my wort.

Ideas?

I did this for mine. Just throwing it out there for an idea.

WortMonger said:

I did this for mine. Just throwing it out there for an idea.

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thanks monger, great idea. kinda what i was looking for. Im worried about the toxicity issue though.

anyone else have other ideas? the more the merrier.

Well, you can use some other kind of covering paint. I would suggest some of the non-volatiles latex paint they use for baby rooms.

Air is a great insulator. What I do is get a food grade pail liner, blow it up, and then tie the end off with a rubberband. Perfect fit every time, and when you are done the pail liner makes a great garbage bag for the spent grain.

RogerMcAllen said:

Air is a great insulator. What I do is get a food grade pail liner, blow it up, and then tie the end off with a rubberband. Perfect fit every time, and when you are done the pail liner makes a great garbage bag for the spent grain.

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forgive the ignorance.. whats a "food grade pail liner?"

HItransplant said:

forgive the ignorance.. whats a "food grade pail liner?"

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It is an FDA approved polyethelyene (good to 190F) bag that is often used to line the inside of a 5 gallon bucket.

Something like this:
http://www.mcmaster.com/#heat-seal-bags/=9pziah
McMaster links don't always seem to work for me, but product #1928T95


I just blow it up like a balloon inside the MLT to occupy all of the head space.

I just hang some towels or blankets over the whole apparatus. After I put the flame out

Then it insulates the sides as well. I've found with 3 towels draped over the pot, and down the sides, it holds the temperature of the pot within a couple of degrees for an hour of mashing.

plaidpaint said:

I just hang some towels or blankets over the whole apparatus. After I put the flame out

Then it insulates the sides as well. I've found with 3 towels draped over the pot, and down the sides, it holds the temperature of the pot within a couple of degrees for an hour of mashing.

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I guess Im worried about the headspace in the bigger pot allowing heat loss, since it sounds like headspace is the enemy. So, Im trying to figure a way to fill the headspace that can vary with the depth of the headspace.

savy?

I don't see why extra headspace would be a problem . Once you put the lid on the pot, the whole headspace will fill with steam and hot air. If you wrap the whole thing in towels, then the headspace is insulated the same as the wort, and won't change the amount of heat loss.

If the steam and hot air are actively leaking out of the system, then it would benefit from an air barrier, such as the bin liner, or you could install a gasket around the lid of the kettle to seal it. Mine's just a 15L stock pot, and it doesn't leak enough steam to worry about.

It's been a while since thermodynamics in university, but I don't think I'm too far wrong

I have used a piece of foam board cut to size, and just wrapped a couple layers of tin foil around it. Worked well when it got nasty I just replaced the foil. Although WortMonger's solution is much more elegant.