A haybox is an insulated box used to hold a pot of food that has been cooked minimally on a stove, letting the ingredients cook slowly until done with no additional energy required. It’s both a great way to save fuel (and lower your carbon footprint), and a convenient way to prepare food in advance and have it cooked, warm and waiting for you at a later time.
Design
Many different materials can be used both for the box and for the insulation. The “traditional” design of a wood or metal box stuffed with straw is not optimal because straw is not a good insulator in this context. The most convenient and effective designs I’ve experimented with are:
Recycled styrofoam box filled with styrofoam panels cut to fit a specific pot or pots
Recycled styrofoam box and “pillows” of styrofoam peanuts fit around the pot(s)
Plastic cooler filled with styrofoam “pillows”, fleece blankets, or down for insulation
I’ve also heard of people using a deep drawer and kitchen towels or rags around the pots, or in Africa they’ve used woven baskets instead of boxes. Experiment – come up with your own design!
Suggestion: If you do any cutting of styrofoam, to avoid making a big ongoing mess with little bits of styrofoam that get all over the place, obtain a hot wire cutter, available at craft stores like Michael’s for under $10 (or borrow mine!).
Principles of Heat Retention
To maximize heat retention, insulation material should have the lowest possible density and the most air (which is why styrofoam works so well). The pot in which the food is cooked should be as close to a sphere as possible. Thus filling a pot almost full is better than using a large pot with less food, spread out on the bottom.
It is ideal to have as much insulation surrounding the pot as the measurement of the pot’s radius. So if your pot measures 6 inches across, ideally you’d have 3 inches of insulation all around it. Also a larger pot of food retains heat better longer, so this method may be less effective for small amounts of food.
Foods that work best for this method are grains, stews and soups – anything you might cook in a crock pot. Because the temperature maintained in the pot is not consistently high, this method may be unsafe for some meats; any meat should be brought to the point of being “done” before placing the pot in the haybox.
Because there is less water lost to evaporation with this method, you can use less liquid than you normally do. For example, I cooked white rice to perfection with 1 3/4 cup of water (rather than my usual 2) per cup of rice.
I’m still experimenting with this. Some sources says food should be done in just twice the normal cooking time. Others advise to leave food in the box for up to 8 hours. Test things out for yourself, and keep records, so you remember what works best.
My experiments and recommendations
White Rice 1 C. white rice, 1 ¾ C. water. Boiled 3 min. Left in box with styrofoam peanuts 6 hours. 114 degrees. Done to perfection.
Brown Rice 2 C. rice, 4 C. water in 2 Qt. pan. Boiled 5 min. Left in box with styrofoam peanuts 7 hours. 115 degrees. Done perfect on top, slightly mushy on bottom.
Brown Rice 1 C. rice, 1 2/3 C. water in 1 Qt. pan. Boiled 5 min. Left in styrofoam peanut box 6 hours. 112 degrees. A little crunchy, not quite done. Maybe because I opened the lid a couple times, and used a small pot.
Oatmeal 1 C. oatmeal, 1 C. water, 1 C. soymilk, cinnamon. Left in styrofoam peanut box 8 hours (overnight). 100 degrees. A little mushy, but yummy. Try a little less liquid next time! And try it with those multigrain cereals that typically take a long time to cook and I’m too impatient to wait for in the morning. Make a bunch to use during the week - refrigerate and reheat in microwave.
Ecovillage Harvest Soup/Stew
[I’ve had great success with soups, using both fleece blanket in a cooler and styrofoam peanut boxes. They were hot (160 degrees) and delicious after 5-6 hours in the box.]
1 onion
1 medium zucchinis or other summer squash
4 cloves garlic
1-2 lbs. fresh tomatoes
1 Qt. fresh tomato juice
1 C. red lentils
2 heaping teaspoons ground coriander
1 bay leaf
½ teaspoon ground cumin
½ teaspoon tumeric
a pinch of allspice
red chili flakes, salt and pepper to taste
In 3 Qt. pot, sautee onion, squash and garlic together in some olive oil until a little soft, add spices and sautee another minute or so. Add chopped tomatoes, tomato juice and lentils, bring to a boil. Place in haybox 5-6 hours.
