Mar 27, 2014 at 12:35 am #1314875
Youtube brought this up as "recommended" for me. Turns out, its pretty good (way way better than most backpacking/UL videos posted on youtube).
Worth watching. Skip the first thirty seconds. He does three set ups of no cozy, single cozy, double cozy in an ~550ml mug, measures temps every five minutes for an hour. Plots results at the end. Beautiful!
4:40 is the graph. After that he does a demo of building them (I didn't watch it as I already know how).
What I'm personally interested in, is how hot do you have to get the water to begin with. With cozy cooking, the temperature drops below 100C (nominal boiling) quite quickly. After that, likely a lot of cooking/rehydrating is still effective for quite some time. What is the best temperature to stop the stove, and stick the cozy on? Also, if you aren't bringing food to the boil, and therefor are unlikely to burn it to the base of your pot, what temperature should you put your food in on the way up? (This is how I used to cook years ago, pasta and rice hiking as a teenager. Never had any trouble, and it saved a lot of overall time. It wasn't until I started cooking at home later in life (late teens, cooked a lot more) that I found out I was "doing it all wrong" by not waiting until the water was boiling to put in my rice or pasta.
So could it be that you just get the water on the stove, get it up to say 40C (~bath temp for baby), put in your food, bring it up to say 80C, then kill the stove and cozy it for 10-20minutes?
CheersMar 27, 2014 at 7:36 am #2086623
Well since you can rehydrate freeze-dried foods with any temperature water I think it is pretty much personal preference. You just have to allow proportionally more time with colder water.
I never bring my water to a boil unless I am trying to sterilize it. The only reason most people get their water so hot is to rehydrate faster and ensure they still have a nice warm meal after it finishes rehydration. I use my pack towel as a cozy since it means I can use less fuel and still have a warm meal.Mar 27, 2014 at 7:53 am #2086628
I had heard and more or less followed the "before-boiling" advice. If it is genuinely fully-dehydrated pre-finished food I think you don't need heat at all – it a all a question of time, and how warm you want to eat it. Always good to know if you run out of fuel you are covered!
What would be interesting, and that I have not seen except for certain items, is a table of sufficient time for different types of food, though I'm sure many items would be edible after 1 hour in cold water most of the time.
I have some dehydrated Chilly Mac I made for backpacking last week. Seems like a good thing to try as an example as it has beans, meat, pasta, and sauce – kind of hits things in the middle of the backpacker dehydrated food groups. I will try this out – put in cold water, and test every 10 minutes for "done-ness" – and report back here. If it works then the issue is more about finding your personal sweet spot in the triangle of how warm you want it to still be when done, how long it need to seep, and how much fuel you want to save.Mar 27, 2014 at 8:00 am #2086633
Chilly Mac is probably a good tester for you US people.
Yep, there would definitely be a patience/heat play-off here. I'm betting its on a nice bell-curve though (the time to cook vs maximum water temp). Require quite a few reps to experiment to produce that curve…
I guess the fuel savings shouldn't be too hard to calculate, it will come down to proportion of delta T you are willing to sacrifice. Ie, if starting temp of water is 20C, and you raise it to 80C, you are doing 60C change, vs 80C change for boiling, so if you normally use 15ml of fuel for your boil, you would now use 60/80*15ml=11.25ml. That's quite a saving, really. If the cozy is facilitating this for you, you won't take long on a trip to pay it back in weight.Mar 27, 2014 at 8:10 am #2086636
"Chilly Mac is probably a good tester for you US people."
Do tell, what would be the equivalent from your side of the globe?
Personally I don't like the traditional "American" mac & cheese stuff, and have not eaten it, except when required for politeness, since I was 9. "Powdered" cheese of indeterminate origins is closer to Soylent Green than I am willing to get unless my life is at stake. I know some PCT and AT thru-hiker swear by the stuff.Mar 27, 2014 at 9:40 am #2086658
Well are we talking about freeze-dried foods or dehydrated foods here? I think that is a pretty important thing to specify…
I bring freeze dried on all my trips but if we are talking dehydrated meals that is another story entirely. Rehydrating dehydrated foods is much more time and energy intensive (15 min – 1+ hours depending) and water temperature plays a much bigger role compared to freeze dried (<5 min).Mar 27, 2014 at 10:35 am #2086675
As I said, dehydrated. Freeze dried is not necessary. Close to boiling takes <= 10 min pretty much for everything with a very few exceptions.
Freeze-dried is more about preserving things for years – that and the chemicals they add. I find the commercial ones, which I have used in the past extensively, VERY unpalatable in comparison with my own dehydrated food, at least based on my experience in the last month. My theory is that most of these, like mountain house, taste like crap, but people (including me) only ate them in the field when they are very hungry. If re-hydrated at home you can get a much clearer idea of how bad they are. That was the crucial test for me. LOL
I just tried cold rehydration with my dehydrated chilimac, and also with some dehydrated basmati because I was interested that as well. I used cold tap water which probably started out close to 40F, but room temp was about 65F. I already of course have experience with re-hydrating this stuff with hot water, and it is perfect in 9-10 minutes.
After 10 minutes both were still crunchy as expected.
After 45 min both were a tiny bit crunchy, but probably possible to fully enjoy. The pasta was done almost immediately, meat at this point was a very tiny bit crunchy. Rice was almost ok, but probably too crunchy to eat – it definitely had not fully absorbed the water yet.
After 1 hour 15 min chilimac was done. Picture was take a bit after that. Meat, macaroni, tomatoes etc. were perfect. Rice was done. The only thing was that about 1 out over every 20 beans had small crunchy spots. Someone with a lot more experience than I have might be able to verify this, but I suspect this might have a lot to do with my lack of finesse doing the dehydration. I read the instruction about the temp and time, but my basic attitude was "who can bother" (I know, typical single male's attitude) and I left the machine on overnight. I know as a fact that I over did the dehydration, probably by a factor of as much as %50 on the time. It would be interesting to know if I used a little more finesse in the dehydration process if it would allow the beans to rehydrate better. It is also possible in the absence of the steam I needed to mix/shake thing more often and that that might have gotten rid of the last of the harder spots.
I think with the proper plan, and patience I might be perfectly happy going stove-less with most of my dehydrated meals. Some of the stuff I would actually normally serve cold fresh, like the orzo dish.Mar 27, 2014 at 11:54 am #2086696
If you are dehydrating your own meals and/or rehydrating dehydrated meals this paper may be of interest to you and answer a lot of your questions
I have personally not had a problem with freeze dried food. I usually make meals with crushed up ramen noodles and add my own seasoning and proteins/veggies.
One of my favorites is ramen noodles and peanuts with curry seasoning. I gladly eat it at home as well sometimes (and I consider myself a pretty good cook). If I'm feeling really fancy I'll bring a 3 oz bottle of seasoned olive on the trail for extra calories and flavor.
If I had a dehydrator I would probably go that route, but as it stands I can make a great tasting (to me) backpacking meal for <.50 a piece that takes <0.5 oz of alcohol to rehydrate into a warm meal. I'd say considering what UL backpacking is all about that is pretty good. Then again, as they say, "Make Your Own Meal" or something like that.
Edit: I know ramen noodles aren't the best for you (not that I use the sauce packets, which are the worst part), but they make up a very small portion of my diet (e.g. 2-4 meals a month) so I live with it.Mar 27, 2014 at 12:05 pm #2086702
Sarah KirkconnellBPL Member
@sarbarLocale: In the shadow of Mt. Rainier
As noted, you can rehydrate most foods with any temp water – as long as you have time and patience ;-) A cozy will help speed it up of course…and keep your meal hot.Mar 27, 2014 at 2:53 pm #2086773
I do enjoy both the speed and the warmth at the end of the day. But it is nice to know you can do this and how long it takes, if only so you can be fearless about running out of fuel.
I probably over stated the badness of the commercial freeze-dried food, but it has always reminded my of TV dinner food – no finesse. I certainly have much more experience with it over the years. Probably just need for my "fanatical convert" stage to wear off. Having exactly the stuff I most like is a big biasing factor.Mar 27, 2014 at 3:34 pm #2086793
Sarah KirkconnellBPL Member
@sarbarLocale: In the shadow of Mt. Rainier
I have often compared commercial freeze-dried meals to Chef Boyardee in cans. It will fill you up, but not necessarily with in depth flavor.
Having said that, freeze-dried components, such as vegetables, fruits, meats and more are well worth it. They should not be over looked IMO :-)Mar 27, 2014 at 4:16 pm #2086808
Hmmm, pretty hard to say to be honest. I really can't think of something that is as universal as "mac and cheese". I've heard that mentioned so many times on BPL over the years…it sounds like all you eat!
I would probably pick a continental brand packet pasta that is similar, say four cheeses or something. Easy to buy around the country from a supermarket.
If I'm bored some weekend in the future I might buy twenty packets of it and do a test to make a bit of a curve up, from about 55C to 100C max temps, in 5C incrememnts (plus some repeats). I'll start from hot and go down, so that I have a rough idea each time what the minimum cook time is so I don't spoil the experiment by repeated sampling!
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