How much insulation is enough on cozies? Yes, it varies with the season, and especially the shape of the container. Cylinders are much more effective than envelopes.

I stopped using Reflectrix because it worked too well, with my having to wait too long for the food to cool to an edible temperature. Burning my tongue is not on my list of what I like about backpacking.

My newly made but untested cozy is quarter inch foam, but eighth inch foam would weigh half as much. What material and what shape of cozy are you using, and why?

Edited by heyyou on 10/22/2012 16:37:06 MDT.

I use a cozy from Pack IT Gourmet which I got free with a meal kit, it weighs 1.5oz and does the job well and does seem overly thick.
I keep my gas can and the water filter inside the cosy at night if its cold.

http://www.packitgourmet.com/Ultralight-Cook-In-Cozy.html

Have you tried regular bubble wrap (basically Reflectix without the aluminum)? You probably have some hanging around so all it will cost is a few minutes with scissors and scotch tape. I haven't had a problem with it being too effective.

Yes, I've used the bubble wrap padded envelopes for freezer bag cooking with the dual purpose of insulation under my balaclava when sleeping, but these days I'm trying to carry just the cookpot with a matching cozy, without the cooking bags.

"The greatest enemy of a good plan is the dream of a perfect plan" attributed to Carl Von Clausewitz by some. I'm always surprised when someone from 200-2000 years ago, speaks about human behavior that exactly matches my situation, today.

I have a cozy made from medium weight fleece (not thick, sheep-like pile)

With mating Velcro closure strips it weighs 1.2 oz. (34 g.)

It is easily washable and insulates so well virtually no heat is felt on the outside after 10 minutes of a 1 qt. freezer bag being inside.

The remaining fleece can be used for mitten shell liners. Mittens are dead easy to sew. Be sure the wrist area is long enough.

I use a DIY Reflectix cozy and I've used a foam sit pad like an envelope and even a wool beanie. I've never needed to squeak out every milliliter of fuel like a thru-hiker would, which is the primary use for a cozy. If your cozy is working too well, why not pull the pot out sooner? Reflectix is pretty light stuff in the quantities to cover a small pot.

I've found cheap car windshield reflectors is the best material. By cheap I mean the ones with foil on one side only, laminated to thin white foam. I got one at the 99 cent store for, what else? 99 cents. Lighter than reflectix if that's important and less bulky. I made a prototype taped together with foil tape, foil side of the material facing in. Some stick on velcro rounds keeps the flap out of the way. It's been through 2 years of use and still going strong.
I'm talking here about a cozie for rehydryting food in a plastic bag. Cozies for pots are off my radar.

+1 Don
the only thing i do differently is i use the reflective side out, as the emissivity of the foil insulates better when on the outside, or is it that it doesn't Emmit the heat of what you want to insulate as much... when i tested it it was a 10 degree difference after 20min... and when i say it like that i no longer think it makes much difference. humm you ever say something out loud and then realize it is kind of ridiculous... but there is is... already said. :)

I made cozies from fleece, 1/8" ccf, bubble wrap and I think one other. All those fancy models aside, I found what works best was a ready-made cozy: washed Mtn House bags.

They flat-out work, are lighter, and pack smaller than anything else I tried. They last for quite awhile too! Super expensive for a cozy, but they do throw in a free meal!