Making and using a Hay Box to cook in

The hay box method of slow cooking food is essentially the predecessor to our modern day Crock-Pots, Thermos flasks and electric slow cookers.
So why bother stowing the slow cooker and going all ‘primitive’? How about quartering your fuel consumption (whether gas/ electric at home or those sticks you have to go find in the woods) for a start?

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That alone should be reason enough but add to that never having to tend the meal once the ingredients are in the pot. There is no risk of burning or over – cooking your food either. Sound too good to be true? It isn’t.
And finally all the materials for this project can usually be scrounged, found, fabricated or ‘borrowed indefinitely’ from a friend.
The basic principle to the hay box is conserving the heat you initially put into the pot and ingredients allowing this to cook the food over a long period of time, rather than expensively having to plough energy into the pot for a considerable amount of time whilst much heat is wasted to the environment.

Hay boxes through history
Hay boxes are once again being employed to great advantage in the modern world and not just by the interested cottage small holder or bush crafter. More notably in developing third world countries such as Kenya the Hay box is being championed by several charities now who aim to help some of the poorest communities in this part of the world cook on incredibly scarce wood fuel supplies.
‘The practical fireless cooker is helping families in Kenya to escape the vicious cycle of poverty that is perpetuated by the sheer struggle to survive.
By making families less dependent on fuel, they no longer have to make the heart breaking choice between sending their children to school and short-term survival, or going to work and collecting wood.’
( http://practicalaction.org/our-work/fireless-cooker)

Closer to home the UK government actively encouraged households during WWII to adopt this method of fuel saving cooking, printing and delivering thousands of flyers on how to make and use them. If only the current powers that be had even a slightest bit of their switched on thinking… but I digress.

Over the Atlantic in America they too adopted this handy DIY device for eking out rationed fuel during the Great depression and like us during WWII also. More and more as the economic situation here at home hits our pockets hard or people start taking an active interest in their own well-being prompted by the recent power cuts, flooding, rioting or whatever; projects like building a hay box rise from our distant past to meet our current needs.
Method
Every now and then poking your head in a skip really pays off! All of the ply wood featured in this blog was found chucked in a skip and not even meant for recycling! Along with these sheets I used some old 2×2 hard wood posts that had been lying around the shed and an assortment of screws from other things I have ‘recycled’ (Girlfriend: ‘horded’).
The first step is to find or make a box large enough to contain your dutch oven, crock-pot or similar. I reckoned on leaving an extra 20cm in all directions around the Dutch oven to fill with the insulation material.

If making your own box you need enough sheet material for the 4 walls, base and lid. Place you cooking vessel inside to see how much space is left for filling with your chosen insulation.

If your sheet material is thick enough you may be able to screw it directly to itself to form the box. The ply I recycled was quite thin so I added four corner posts to which I glued and screwed the ply. I started by fixing the four posts to the base sheet

On two of the wall sheets I fabricated a couple of handles from some scrap wood and rope by drilling through the wood block inserting the rope and then tying stopper knots.

To the lid I glued and tacked some rails to help form a snug fit when the lid was inserted into the top of the plywood bow. With the lid fitted you’re almost done.

I recently ‘acquired’ some fibre board which I had just enough of to line the inside of the ply box. This will help dramatically improve the thermal insulation properties of the box. These fibre board sheets are simply placed against the walls between the upright posts. I also cut a sheet for the floor and a second to put directly under the ply lid.

A local farmer kindly donated a bin liner of hay which after placing the Dutch oven inside was used to stuff all the way around and under the cooking pot.

The following morning ingredients were prepared for a beef casserole and once everything was up to a good strong boil on the hob (15 minutes of gas) the Dutch oven was put into the hay box. More hay was placed on top of the pot, the fibre board lid added and then finally sealed with the ply board lid.

Off to work (The World of Bushcraft) I went for the day and when I returned home (8.5 hours later) I opened the hay box and cracked the lid of the Dutch oven to test the temperature.

So after almost 9 hours the temperature had dropped to 40 degrees Celsius from the initial boiling on the hob. Not bad! All that required now was to bring the contents back to serving temperature (5 minutes of gas). So all together 20 minutes of fuel was used compared to the 2 hours + that usually is consumed for this recipe.

Suggested improvements
· Line the box in between the ply and fibre board with heavy duty paper or card, over lapping at the seams to further improve the thermal retention.
· Wrap Dutch oven in an old towel or stuff a pillow case or similar with hay to form a cushion to sit on top of Dutch oven in use – both would prevent bits of hay getting into the oven or sticking around the top waiting to fall in when the lid is removed.
· Make a handle for the lid and clamps to hold it in place during use (I piled heavy books on top).
· Don’t invite the dog to dinner.

Important points on using your hay box
Tightly packed hay or similar is capable of insulating food in a good hay box for up to 8 hours. The efficiency of your hay box will however be effected depending on the environment it is working in i.e. indoors or in the woods during winter. Where possible place the box in a warm place.
Food hazards: Most food can be re heated safely after it has cooled gradually but foods such as rice should not be cooked in this way as there is a potential for toxins to form which may not break down on re heating. Always follow cooking advice for each food type you intend to cook in this way.
Just like your outdoor clothing if the hay gets damp it won’t insulate half as well so dry the intended materials first – I heated the empty dutch oven first in the oven then stuffed it in the box with the damp hay, this quickly expelled the moisture and although this used extra fuel it only needs doing the first time round as you can re-use the same hay each time!

Variations
Other designs including card board boxes, old ammo tins (id question the transfer of heat here compared to a wooden box) and even Cool boxes (Styro foam lined) can be ideal.

The stuffing can be old wool jumpers, saw dust, moss or any dead dry fibrous material. I should think dead bracken, cleavers or even beech leaves – all excellent shelter insulators and available en mass usually- can be utilised. Or if at home/ work, try emptying the office shredder paper in their or use that spare emergency blanket from your first aid kit.
Use your imagination, improvise and adapt to what’s around you and have fun with it!
And finally..

If all the above has not persuaded you to give this fantastic home project a go here’s a killer recipe from our Dutch Oven coobook that we regularly use in the woods on our 5 day survival course to get your creative juices flowing: ‘Poyke’ pot stew recipe for venison (beef works just as well)

24 hour Marinade for meat: fresh thyme, bay leaves, onion, garlic, red wine, black pepper corns.

Method: Brown meat and onions in oil strain marinade back on top add potatoes, carrot, leek  and give it a long slow cook. Stir in half I little jar of red currant jelly.
Adam Logan
Bushcraft Instructor for Woodland Ways.

Don’t forget you can also join one of our survival courses in the UK to learn more interesting bushcraft skills.