Comments About Thermal Cooking and Retained Heat Methods and Recipes


Welcome to the thermal cooker, thermo cooking blog where I will be collecting and sharing information on the methods and functions of using non-electric retained heat cookers and cooking methods.

I will collect information on thermal cookers, hay-box cookers, fireless cookers, vacuum flasks and wonderboxes that use the method of an insulated container or shell to retain the heat inside an inner pot that holds the food that is being cooked.

Take a look through the categories on the left for recipes, demonstration videos and information on all kinds of thermal or retained heat cookers and how to make and use them.

23 Responses to “Comments About Thermal Cooking and Retained Heat Methods and Recipes”

  1. danamccauley Says:


    Have you tried using a parabolic solar cooker at all? I’m hoping to try that method myself this summer and would love to get tips on using solar equipment.

  2. thermalcooker Says:

    Though I’ve watched a solar cooker do it’s thing and have heard many describe it’s great uses, I’ve not run one myself… yet.
    I great resource on the genre is available at:
    I believe a solar heat source would work very well with a thermal cooker. A thermal cooker would offer an advantage when the sun isn’t out in full force to keep what heat is being generated in the short times the sun would be shining to cook a meal. A site down under: shows a thermos thermal cooker being used in a solar parabolic reflector cooker.

  3. Marita Says:

    Last week I cooked a breast of chicken in a solar funnel cooker here in So. Calif.

    I use a mylar sun shade molded into a funnel. I put a plastic tray underneath the mylar funnel, a black aluminum grate inside the funnel. I put the seasoned chicken in a small cast iron skillett and inserted a thermometer in the meat. I enclosed it in a clear plastic bag with the ends held closed with a clip.

    The temperature of the thermometer was 60ºF and in 30 minutes the temperature was 120º F. I cooked for 2 hours when the internal temperature of the meat reached 160º.

    The meat was moist and tasted delicious.

    I next tried corn bread, but used shiny aluminum cupcake pans lined with paper cups. It didn’t work and I think it is because it needed something black around it. I will try it again this week with a black cupcake pan.

  4. sock Says:

    how do you make yogurt and tofu with the thermal pot? Could you please share that secret!? Thanks

  5. thermalcooker Says:

    Making yogurt was one of the first applications we used our thermal cooker for. It makes the process almost effortless. Just before going to bed I would start the process by pouring 4 quarts of raw sweet Nubian goat milk (cow milk works too the more fat content the better) into the stainless steel inner container and place it on the stove. While monitoring it with a thermometer I’d bring the milk temperature to around 110 degrees (don’t exceed 118 degrees). I would add two packages of Yogourmet yogurt starter to the milk after the temp reached 100 degrees and would stir it in as the temperature rose the final 10 degrees. Once it reached 110 I would place the lid on the cooker and place it into the thermal outer container and set it aside and leave it until the morning. When I’d wake up I’d take out the inner pot and place it and the finished yogurt contents into the refrigerator. It’s that simple.

    For future batches I would leave about 1/2 a cup to 1 cup in the container and add new milk over top of it as I heated it up to 110 repeating the process above but without adding any additional starter packages. We would make 4 or 5 batches before adding another starter pack to keep the cultures thriving.

    I haven’t had the experience yet of making tofu so someone else will need to chime in on that process.

  6. Allan Says:

    Hi there,
    I aam impressed with the range of information that you have available on your Blog.
    I also noticed that you have posted quite a few of the recipes from our web site…I don’t have a problem with this infact you will find our new web site has many morte recipes that you can use…I would ask that you provide a link back to our web site when using these recipes or any other information that you may want to refer to from our web site.
    We also have a series of cooking demonstrations available for viewing if you would like to link across to them.
    If you have any other queries or questions about just how beneficial thermal cooking is or how to use thermal cookers for baking bread (excellent for all the Gluten intolerant travellers) etc please do not hesitate to drop us a line.

    regards and keep up the good work

    Thermal Cookware

  7. thermalcooker Says:

    Thanks Allan, I am a great fan of your site for it’s info and now demos of thermal cooking. It’s one of the first sites I found on thermal cooking and with the new additions you’ve been making it’s become an invaluable resource.

    Some of the first recipes I had were from the recipe book that came with my Thermos thermal cooker and they match what was on your site. I appreciate that your site was one of the first and only to even have recipes listed. I gladly added a link back from the recipes here to your site to get people looking your direction and to the excellent demonstration videos you have. They are a great help and wonderful examples on cooking with a thermal cooker!

    Thanks for all the help from all of us who are fans of thermal cooking!

  8. Maggie Says:

    I am very interested to purchase a thermal cooker. However, I just updated my kitchen with a new induction cooktop. Could anyone tell me if the inner container works for the induction cooktop or not?

  9. thermalcooker Says:

    Maggie, not all thermal cookers are made the same. Of the three different brand commercial thermal cookers I have only the Thermos brand passes the induction test where a magnet will stick to the bottom of the inner pot.

    The clad bottom on the Thermos inner pots are conductive and should transfer the heat to the rest of the pot. For some reason though the upper part or everything but the clad bottom of the inner pot is not magnetic. I thought all stainless steel pots would be magnetic but I was wrong and found that out when testing the other inner pots. Evidently these stainless steel pots have a high nickel content which makes them non-magnetic.

  10. outdoorsrusonline Says:

    Thermal Cooker,
    I too am very impressed with the range and depth of information you have pertaining to thermal cooking. I was also pleasantly surprised to find you have also referenced my site in your blog ( I wanted to drop you a note saying Thanks!
    I am completely new to blogging. I just recently started a blog of my own where i want to start posting reviews of Thermos products. I started with the Thermos Cook and Carry, which is how i also stubled upon your blog.

    Stay in touch and feel free to leave Thermos products input and reviews if you have any!

    Brad – Outdoors R Us

  11. Newbie Says:

    Has anyone had any failures with their thermal cooking? Or is it just me? 😦

  12. thermalcooker Says:

    Failures? As in the food not cooking? Yes I have! However, I could lump most failures under the category of not having enough food or water in the cooker sufficient enough to retain heat needed to cook the food. The thermal cooker will only work if it can keep or retain the heat provided in the initial boiling/simmering of the food long enough to cook it. If the cooker’s inner pot is half empty there likely won’t be enough thermal mass present to hold onto the heat long enough to cook the food. Empty air is a very poor conductor of heat so an empty pot will lose heat much much faster than a pot full of water or food.

    Another thing to watch for is the length of time you keep the food at a boil. Some recipes and food types cook much faster than others so you will need to adjust the “time on the stove” accordingly to ensure that the food will finish cooking with the heat that is retained inside.

    For example, a pot of oatmeal only needs to be boiled about a minute to ensure it will have enough heat to finish cooking but a recipe with large vegetable chunks and whole chicken parts or a big side of beef is going to take a minimum of 20 minutes at a boil before the centers of the meat and vegetables have heated up sufficiently to cook once the heat is removed and the pot is placed in the thermal cooker.

    Note that all thermal cookers or retained heat methods aren’t created equal. Some are much better at holding in and retaining the heat than others. Even among commercial thermal cookers some are made with a thin foam lining that don’t do very well at retaining the heat for longer periods of time. Recipes that would cook easily in a cooker with a vacuum insulated outerpot may fail to finish cooking in a pot with a thin foam insulated outerpot because they just won’t hold in the heat.

    There is a big difference in performance between cookers that cost $50, $60 and those that typically sell for over $150 and are vacuum insulated. I’ve performed tests where I will bring a full pot of water to a rolling boil and then place it in the thermal cooker. The $50 dollar model’s water temperature was 40+ degrees F less after 10 hours compared to the vacuum insulted versions. The Thermos vacuum insulated model was still above 140 degrees after 12 hours.

  13. prortuamoum Says:

    Outstanding article – i will come back=D

  14. thermalcooker Says:

    Here are a few new sites that have some good information on thermal cooking:

  15. Allan Says:

    Hi there,
    We have expanded our range of Thermal Cookware to include a large single 6 litre model and we have also expanded our range of Stainless Steel cooking accessories so that you can enhance the total cooking experience.
    Have a look at a new web site for a growing community of Thermal Cooking newbies and experts all of whom are willing to share advice and recipes.
    Happy cooking

  16. Aluminum Grating, Steel Grating Says:

    Note that all thermal cookers or retained heat methods aren’t created equal. Some are much better at holding in and retaining the heat than others. Even among commercial thermal cookers some are made with a thin foam lining that don’t do very well at retaining the heat for longer periods of time.

  17. Johanna Mpyane Says:

    I would like to keep in touch with people in the business who can help me restart the wonderbox business since its now very viable because of the shortage of cooking energy like wood, electricity, etc. Preferably from South Africa since they are my neighbours!

  18. Owen Geiger Says:

    Outstanding article and blog. I’ve added a slight twist to retained heat cooking. You could use a rocket stove for the initial boiling period that’s fired with twigs and branches to essentially slash the cooking fuel cost to nothing. You could call this zero energy cooking. I just posted this idea on our Natural Building Blog

    Kind regards.

  19. Still Curious Says:

    Cooked Qinoa today in my Tamaya 1.5 (2?) liter multi-function thermo pot.

    4 cups water
    2 cups qinoa
    Boiled for 2-4 minutes. Sealed in the insulated pot for 20 minutes. Set the inner pot on the counter for a few minutes more then fluffed and left to cool for later use.

    I am experimenting with muffin recipes that use cooked, cooled qinoa.

    I searched for a Tamaya pot like mine today but only found the wholesalers site. Equivalent pots cost much more then I paid for mine.

    I am looking forward to reading recipes in the fireless cookbooks and blog

  20. Chassidy Says:

    It’s a shame you don’t have a donate button!
    I’d certainly donate to this superb blog! I guess for now i’ll
    settle for bookmarking and adding your RSS
    feed to my Google account. I look forward to fresh updates and will share this website with
    my Facebook group. Chat soon!

  21. Gabriela Salsamendi Says:

    Hola, soy maestra y estoy trabajando en escuelas de Uruguay con estas tecnologías apropiadas en la construcción y uso. Además estoy trabajando vinculando esta tarea con el programa curricular vigente y para que estas tecnologías, como la Olla bruja, el calentador solar, las cocinas solares, lleguen a las comunidades.
    Me encantaría intercambiar información con otros docentes de otros lugares que sigan esta línea de trabajo.

  22. barry Says:

    where can i buy a receipt book for my thermo pot,please

  23. Jan Butterworth Says:

    Good morning….I am new to thermo pit cooking. Yesterday I cooked a beef casserole using1kg blade beef, 1kg vegetable and 1/2 cup of red wine with some herbs . We simmered for 20 minutes and using the large inner pot only, we put it into our thermoplastic ( in our case a n Eco pot. 8 hours later the meat was still unpleasantly tough. This morning I re simmered on the stove, and gave it some more hours in the thermo pot, and eventually achieved a good result. Should we have put boiling water in the small inner pot, or cooked something else in to retain the cooking process more effectively? Blogging from Australia incidentally….

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