How to make a ground oven
The ground oven, also known as an earth oven is one of the oldest forms of cooking, and evidence for the use of a ground oven goes right back to the end of the ice age 12,000 years ago. It’s one of the best ways to cook meat and vegetables while out in the wild, and it couldn’t be easier to make one. All you’ll need is a digging tool and several rocks to line the edges and bottom.
Step 1 – Digging
The main thing to check before digging is that the earth isn’t too wet and isn’t made up of peat which can catch and smolder for a long time. The hole you should dig would depend on the size of whatever it is you are cooking, a special dish in Morocco is the cooking of an entire sheep in the same ground oven. It doesn’t matter if it’s a round, circle, or a square hole, just make sure it’s deep enough to fit your rocks under and above the thing you’re cooking plus 6 inches of extra room on top.
Step 2 – Rock lining
You can use any kind of rocks for lining the bottom and edges of your hole, but be careful not to use any rocks that contain flint as these can sometimes explode when they get hot enough. It’s also a good idea to avoid using rocks from the bottom of any kind of body of water, including rivers and the sea as these can sometimes also crack open with considerable force on heating. Line the bottom and sides of the hole with your rocks which should match the size of what you’re cooking. The larger the stone the longer it will hold the heat but the longer it will take to get hot enough, also very large rocks get a little too hot and would scorch something like a rabbit, so use the right-sized rocks for your food.
Step 3 – Heating
Make a fire in your rock-lined hole and keep it burning for preferably at least an hour. After the fire is going put a few extra rocks on top, which will be used later to lay on top of your food, but be careful not to smother the flames.
Step 4 – Cleaning out and filling in
Scrape out as much of the ash as possible and remove the extra rocks you put on top of the fire, but don’t remove any of the floor or wall lining rocks, and if any of them move just put them back in place.
Next, you need to add your cooking item, which can be put directly on the rocks but it’s often better to find something to protect it to stop the outside from burning. If you can find any, wrapping meat in burdock or wild garlic leaves works quite nicely, but generally, any kind of edible leaf or some tin foil will do the trick. After the cooking items are in place, put the extra rocks gently on top and prepare for the covering.
Step 5 – Covering
A ground oven works by trapping in the heat and slow cooking the food, and to make sure the heat stays in for long enough you’ll need to make a covering. Find several straight sticks and lay them over the opening close enough together to cover it and stop the top layer from falling through. Next, you need to move some soil or sand on top to make an air-tight seal to trap the heat, but before you start shoveling it on, it is often a good idea to put some smaller sticks or a layer of leaves on first to keep as much soil as possible out the hole. After covering the hole, smooth over the top and make sure it creates a seal, with no small holes venting the heat out.
(An example of a traditional Māori ground oven)
Ground oven Cooking times
As for cooking times it of course depends on what you’re cooking, for example rabbit or rabbit-sized game will normally take about 2 hours, but this can vary a lot with how many rocks you use, how thick they are, and how big your fire was, so give any kind of meat at least an hour and a half, with roots and vegetables normally taking much longer than meat.
Steaming
One of the great things about this type of oven is it also allows the option of steaming your food, which works great with any kind of fish. After the oven is all finished and smoothed over, poke a small hole somewhere near the edge and pour a little water in there before covering it back up again. This works best with fish and vegetables but isn’t necessary with meat, as cooking in this fashion makes any kind of meat very tender on its own.