Re: rehydrating (prepackaged) food in cook pot vs. foil pouch

My normal dinners are Mountain House dehydrated meals. They come in a foil/poly pouch which is used for rehydrating. Just boil water in a pot, pour into the pouch, reseal the pouch, wait ~10 minutes and eat.

Now I'm going to try rehydrating and eating from the cook pot. I'll repackage the food from the heavier, thicker, larger (harder to pack) MH pouches into regular Ziploc-type bags. That should save (a tiny bit of) weight, but more importantly make it easier to fit more food into a bear canister. It will also be a stepping stone to trying out some other food, with fewer additives, etc.

Over on BPL it seems that it's accepted wisdom that one *must* have a cozy for a cook pot used for rehydrating a meal. I have an MSR Titan Kettle (Ti). The walls are thin and Ti has low heat mass, but it does have a tight fitting lid and I thought it would be at least as good as the pouch.

Can anyone comment from experience with the two methods? A cozy will certainly keep things warmer, longer, but is it really needed to get the same thoroughness of rehydration in the same time as the pouch? A cozy is yet another thing to remember and take care of; if the bare pot is no worse than the pouch I'll skip the cozy - which I'll have to make myself, which is OK if needed.

Thanks.



Edited 1 time(s). Last edit at 06/29/2016 12:05PM by ags.

The main advantage of the cozy is that the contents stay warmer, so the hydration time is shorter. You can make a cozy out of any insulated material--I use mylar-coated "bubblewrap" that's intended for insulating ducts and weighs very little. You can buy a huge roll of it at a hardware store. But, if you're careful about spills, you could use your hat, jacket, or sleeping bag as a cozie, but consider putting the pot in something like a plastic grocery store or trash bag just in case there's a small spill or to keep any steam from getting into your down.

You can also empty the contents of the MH foil pouches into sandwich-grade (non-freezer) zip-locks, flatten the pouches, and refill and rehydrate at dinnertime. Once emptied and flattened the pouches take up little space in a bear canister, and you can actually re-use the pouches (but be careful with the zip seal on them--that is their weak spot!). Or, slit the pouches above the zip seal, squeeze out all the air, and re-seal--although the pleated bottoms are still a bit inefficient space-wise. Some people are OK rehydrating in zip-lock bags, but the freezer bags needed for this are about the same bulk as the MH pouches, and the MH pouches are much less likely to leak (except for those wonky zip seals...).

Thanks for the replies. All good points. I've been using MH in the Sierra for years, and have that pretty well figured out. Always end up with a hot, well-reconstituted meal. As noted, biggest issues are expanding menu beyond MH food and packing into a canister. The MH pouches (pleated bottom mostly, I suppose) don't pack that well.

Mainly I'm wondering if a Ti pot is really much different (in heat retention) than the MH pouch. The pouches do seal well, but they are even thinner-walled than the Ti pot (which does have a lid). If I can expect similar heat retention using the pot I'm all set; if not, I'll make a couple of cozies from the reflectix material as has been discussed extensively in other forums.

Downside to eating from the pot is:

1) extra step to repackage food from MH pouch to standard Ziploc pouches.
2) will need to clean out the pot after eating
3) will need two pots now for two people

Benefits of eating from the pot:

1) not cooking in plastic (unclear risk, but some have raised concerns)
2) more "packability" in bear canister
3) can expand menu to include other foods that don't come in cooking pouches (could purchase/reuse pouches as an alternative though)

I suppose I could repackage the MH meals into Ziploc bags for packing in the canister, but also bring the empty, flattened MH pouches and cook in them. I suppose I could just bring two MH pouches and reuse, but then it will require rinsing/cleaning and still probably get nasty after a week. That just seems to be adding more steps for little benefit.

A cozy definitely helps. Consider: that dried food rehydrates faster and more thoroughly when the water-food mix is warmer rather than colder, and further consider that rehydration takes longer at altitude. Typical instructions on freeze-dried food packages are that the recommended time is calculated for at a 5,000 ft altitude and further that you should double that time for each additional 5,000 ft. So basically double it for a typical Yosemite campsite at 10k, so that could be 30+ minutes. Put these two considerations together and you have a situation where the rehydrating food will cool off over that longer wait time and thus won't rehydrate as well. And won't be as hot when you eat it, either. So insulation definitely helps.

You don't specifically need a purpose-built cozy, people have used their sleep pad, fleece cap, spare socks, down puffy, etc for insulating their food. I made a cozy from a reflectix-like windshield screen, weighs less than an ounce and works well.

Separately, I eat directly out of the zip bag rather than put the food directly into the pot, no clean-up that way. My cook kit has a caddy that I use rather than the pot, but same idea -- I just put the zip bag of food into the cozy, pour the boiling water into the zip bag, seal it and wrap the cozy, works well. If you do this you definitely want to use thicker freezer-bag zippies, not the thin "everyday" ones, to stand up to the boiling water. Some people are concerned that the boiling water will leach chemicals out of the zip bag into the food, but I've also heard that the plastic is designed to hold up to boiling water. In any event I've never tasted anything in the food and no brain damage as far as I know...

We used a towel for a cozy for years..but then made one out of blue foam. And it makes a difference. Doesn't weigh much, and fits into the pack with the cookset

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Quote
balzaccom
We used a towel for a cozy for years..but then made one out of blue foam. And it makes a difference. Doesn't weigh much, and fits into the pack with the cookset

Yup, I saw that on your site when I first read it many years ago. Very clever. I already have the Reflectix to use if I decide to fashion a cozy. On the one hand I could make it, try it, and not use it again if I don't like/need it. On the other hand, I could try without and then if unsatisfactory, just make it and bring it on the next trip.

I'm changing so many things in my standard "go to" kit on this trip that I don't know where to begin... It will be fun no matter what.

Never been a fan of the MH stuff, to many preservatives and I just don't like the flavor of most of them. Because of this I tend to dehydrate and make most of my own food and what I don't do homemade I buy from PackitGourmet (Amazing stuff there) because of this I almost always just end up doing ziplocks and then cook in my pot and Believe me you need the cozy, especially if its gonna be the least bit cold or breezy. With my Relfectix cozy I boil the water with the food and stick it aside for awhile to rehydrate and by the time its ready to eat it can sometimes still be too hot which is wonderful on a cold night or morning. A simple test you can do at home is to boil a cup of Hot Cocoa or Coffee and put it in your cook pot and let sit for a good 15-20mins and then come back and feel the temperature difference. Take into account the fact that it will be colder outside, the wait time for your dish longer and the altitude higher means that if that drink isn't still to hot to drink after 20mins on your kitchen counter then it will definitely be to cold for my taste to eat.

That's a great idea. I should have thought about that - use the scientific method. Boil 16 oz of water (typical for rehydration) and seal in an (empty) MH pouch and the same amount in a covered Ti cook pot. Wait 10 minutes (typical rehydration time) and measure the temperature and compare.

What amazes me is that I would never have considered that the very thin MH pouch walls could be better insulators than the Ti pot walls. If that is true, then a cozy is needed. If not, then since I've been perfectly happy with the thermal properties of the MH pouches, the cozy isn't needed. Note that at the moment I'm thinking of typical ambient temperatures in the Sierra May-October. Typical morning lows of mid-30's or so. Winter might present an entirely different result.

reflectex is a very good insulator close to weightless. not familiar with your pot or stove, but for years my partner and I re-hydrated in pouch {manufacturer's or freezer bag} let it sit a while, then brought an inch or so of water to boil in the pot, and placed the pouch in boiling water to finish re-hydration/re-heating. the additional fuel use is minuscule, and the hot water is useful after dinner. of course, you may have to carry a few extra grams of fuel, if that's a big problem for you.



Edited 3 time(s). Last edit at 06/30/2016 09:57AM by mkbgdns.