instructables – haybox cooker

Haybox or retained heat cooking is simply cooking a liquid based food like a soup or stew in it’s own heat. During WWII cooking oil was rationed for the war effort this method became popular as a way to conserve cooking fuel. They used hay in a box because the air spaces in the hay trapped in heat and allowed the soup or stew to cook in it’s own heat. Anything like hay, shredded news paper, rice hulls, cotton balls, corn husks etc will work as long as it packs loose and creates air spaces.




A haybox is an insulated container which can make significant fuel savings – up to 70%! Just bring the food to a boil, place the pot inside the haybox, and cover. The haybox will contain the heat in the food so that it will continue cooking without using extra fuel. In terms of our three heat concepts, a haybox works by maximizing heat storage and minimizing heat loss. A haybox is ideal for foods with a high water content like soups, stews, rice, boiled eggs and more. Foods which lose a lot of steam on the stove can be cooked with less water using a haybox.

You can precook the beans and legumes in some recipes, such as chili, in the haybox before adding other ingredients, since some beans must be boiled for at least 10 to 15 minutes to make them safe to eat.


Hayboxes can also be used to raise bread or incubate yogurt or tempeh. Place a container of hot water in the haybox to keep the temperature up.

You can use a cooler as part of a haybox, but you will probably want to add more insulation. You can make a haybox from all sorts of local materials, such as a basket filled with dried grass and covered with a bag or pillowcase of dried grass on top.

Cooking times:

Food: Boil time: Haybox time:
Rice 5 min 1-1.5 hours
Potatoes 5 min 1-2 h
Soup and stock 10 min 2-3 h
Green Lentils 10 min 3-4 h
Pintos 10 min 3 h
Split Peas 10 min 2 h
Quinoa 5 min 1.5 h
Millet 5 min 1 h
Polenta 1 min 1 h
Winter Squash 5 min 1-2 h
Steamed bread 30 min 3 h
Chicken 6 min 2-3 h
Beef 13 min 3-4 h

Haybox Notes:
Aprovecho’s Guide to Hayboxes and Fireless Cooking, by Peter Scott, et al. Aprovecho Research Centre. (Brochure)
Fireless Cooking, by Heidi Kirschner, Madrona Publishers. 1981.

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