My Blog List

Thursday, December 31, 2009

Thermos Cooking

I've wanted to do Thermos Cooking for a while.  The general idea is, you add boiling water to a food, put it in a thermos, and let it slow cook.

I've done little tests in the past, but they were with the cheaper plastic lined deals.  All of the research I did indicated that you needed to use a high quality, stainless steel-lined thermos.

My past tests certainly indicated that the plastic models would not work - even with rice.  So I broke out my trust Stanley one quart thermos to give it a shot.


I started with beans.  I soaked one cup of red beans over night.  The next morning, I took the soaked beans, two and a half cups of water and some spices, and brought them to a boil.  I covered them and let them boil for 5 minutes.

The beans, spices and liquids were placed in the thermos, given a good shake, and placed on their side.  Every article I had read said to do this to ensure the greatest coverage of water over whatever is being cooked.

I then waited for 6 hours, giving the thermos a shake ever hour or so just to make sure everything was staying covered.

The result?  Total failure.

The beans were still way too hard to eat.  I have a plan to fix this, though (later).


Next up were pastas.  Everything I read said that this was a natural for thermos cooking.

I started with orzo.  Personally, I love the shape and cooked texture of orzo.  It is a small, oval-shaped pasta.  I like it for my preps as well because it doesn't have any sharp edges.  This ensures it doesn't pierce my vacuum-sealed bags like spaghetti and other dry pasta have a tendency to do.

I poured one cup of orzo into the thermos, and covered it with about 3 cups of boiling water.  I sealed it, gave it a shake, and placed it on its side for 25 minutes (regular orzo takes about 9 minutes of boiling).

After the allotted time, I poured the contents into a strainer.  It appeared that not all of the orzo came out.  Perhaps half came out, with the other half stuck to the bottom of the thermos in a big ball.

Apparently, there was still a bit of water in the bottom of the thermos, and it made the orzo stick to it - enough so that even when I shook up the thermos, it did not dislodge from the bottom.

I was eventually able to get it out, and I must say, the orzo was cooked perfectly.  Just a bit al dente, which is how I like it.

Next up was curly-Q pasta (I forget what its real name might be).  It's that corkscrew-looking stuff.  This time, to prevent the sticking pasta problem, I added about a cup of boiling water, THEN a cup of the pasta, and covered that with another 2 cups of  boiling water.  Like the orzo, this had a regular cook time of 9 minutes, so I sealed up the thermos, shook it for good measure, placed it on its side, and set the timer for 25 minutes.

I poured this out into the strainer, and it too was cooked perfectly.  It was a bit broken up, so I'm guessing that it could have spent a little less time in the thermos.


Lastly, I did whole-grain wheat - hard winter red wheat, to be precise.

I poured in 3/4 of the wheat, covered it with 3 cups of water, gave it a big shake, and set it on its side.

The next morning, I strained it, and it was perfectly cooked, but cold.  I estimate it was in there for 12 hours.  I took some of the wheat, added a bit of milk and sugar, and had a bowl for breakfast.

It's not really my favorite way of eating rehydrated wheat berries.  I prefer them added to a salad or mixed in with some sort of savory dish.  They're a bit too rubbery/chewy to eat all by themselves, IMO.


So what did I learn?

Large whole beans will likely never be able to become a meal in thermos cooking.  In my next test, I'm going to try lentils and split peas to see if they work better.  Also, I'm going to try the fully-cook, dehydrated beans I made a while back (see here for specifics).

Pasta is the big winner, especially if you were in a situation where you HAD TO conserve fuel.  Instead of burning fuel for about 14 minutes (5 to bring it to boil, and then boiling the pasta for another 9 minutes), you can cut that to just the 5 minutes it takes to bring the water to boil.  Total cook-time is doubled, but fuel usage is only 1/3 of normal.

The wheat was a winner as well - performing as expected, but it just isn't my cup-of-tea when eaten by itself.  In terms of fuel savings, wheat would be the clear winner, as it can take an hour to boil up kernels to the tender stage.  Personally, I just need to find some more uses of the boiled-up kernels.

My next set of experiments will also include some full meals.  I found a couple of them on the Internet, which I may tweak and take a stab at.

Lastly, get a wide-mouth thermos.  I had the regular type, and it's a pain getting the water and foodstuffs in and out of there.

Accept The Challenge

Finding alternate ways of preparing food, especially under difficult conditions, should be a part of everyone's prep skills.  Thermos cooking, while significantly increasing the cook time of a food, offers a fantastic alternative, especially when cooking fuel is at a premium.

Identify some foods you enjoy, and test some small portions to see how they turn out when cooked in a thermos. 

Copyright 2009 Bison Risk Management Associates. All rights reserved. You are encouraged to repost this information so long as it is credited to Bison Risk Management Associates.


Andrea said...

This is something I've been considering for a while; and conveniently enough, my husband got a stainless steel Stanley thermos for Christmas :) I use a thermos for making yogurt, but that's as far as I've gotten in terms of Thermos cooking.

Chief Instructor said...

It is something that I'll practice with for emergencies, but it's not one of those techniques that is worth the effort for day-to-day cooking.

Ryan said...

I fiddled with Thermos cooking for awhile a couple years back. I got a Thermos just for this purpose a couple years ago. The one I chose was the smaller squat Stanley model. I chose it because the lid is the same size as the barrel and it is relatively shallow which means I can scoop stuff out of it with a spoon or wash it.

Recall that I got some sort of mid sized beans (split beans I think or maybe they were lentils) to cook all the way through. To do so I filled the thing to the top with boiling water and left it for a pretty long time. More like 8-9 hours I think.

These days I want to get a new 1 qt just for coffee. Tis on the list. Always lots of stuff that costs $30 or so that you can kinda use. May have to fiddle with Thermos cooking again. Pasta sounds promising.

Anonymous said...

iv been wanting to try this, but the heat can get so hott that it might break the rubber seal in the stopper

tvnewsbadge said...

Sorry to hear your experiments did not work. I've been Thermos Cooking for years and have found it to be a complete joy.

The key is to pick the right foods and the right foods are hard to cook whole grains, wild rice, hull less barley, oat grouts, flax...

These cook up great without spending half a day tending a hot stove or waste hours of fuel.