So here was the idea behind this project: Can I cook meat underground with as little expense, but still create a great meal?
As it turns out, YES you can!
The meat prep and seasoning recipe is at the end of this Instructable. Have fun with the recipe!
Given this will be an open pit of flame, please make sure your area, city, or county allows for this type of burning. One city I lived in had requirements that included keeping your wood pile a certain number of feet from your ground pit. Also, if you are going to do this in town or near your home, locate all buried electrical, water, sewage, and gas lines. During your wood burning would be a terrible time to locate your buried gas line! :D
Making the ground pit
Tools: digging devices. Shovel, rock bar (if needed), auger (if available)
rock devices. hammer, sledge, chisels (if available)
I created my pit in an open area near an existing burn pile. This meant the soil had already been cleared of debris that could catch fire. I checked the dimensions of my round grill to determine the size of my hole.
In my area, a rock bar is a necessity. You may not need one in your area, but you will quickly determine that as you dig.
I laid out a 2ft by 2ft square pattern in the ground first. Then I used an auger attached to a tractor to drill holes inside of the square pattern. This helped to loosen the soil, which made digging much easier. If you don't have an auger, the it might help to moisten the soil to make digging easier. I dug the hole out to a depth of 18 inches. The bottom of my hole happens to be a semi-solid rock layer, which makes for a good base.
Next, I used a sharp shooter shovel to square up the sides. This is not needed, but I couldn't leave it out of square!
Here is what the hole looks like after my first cooking. As you can tell, the work to make the hole look nice didn't last long. Oh well!
Next, I collected rocks from the area that were approximately the same height. I set the first rock on one side, then filled in the rest of the sides. The last rock I had to chisel a bit to make it fit. Once they were all in place I tested the height by placing my grill on top of the rocks. The rocks formed a nice coal chamber for the grill.
To finish off the ground pit, I found a nice sheet of metal roofing for the lid. We happened to have the right piece for this (No cost!). If you do not have any sheet metal laying around, call a local roofing company to see if they have a remnant piece you can have/purchase cheap.
Step 1: Prepping the Pit
We have an abundance of oak firewood from dead trees, so I am using this wood as our heat source (No cost!). You can use charcoal if you want.
Also, I cut small logs into discs for the smoking stage. You will need to soak the chips over night for smoking the meat. More details in a later step.
I stacked the logs inside of the pit as shown in the picture. If you notice in the center of the stack, there is a brown paper sack. Our local grocery store still stocks paper sacks and I prefer them over the plastic ones. I fill the sack with dry leaves and roll it into a starter log for my grill. It is free fire starter material and free of petroleum materials (no charcoal light fluid!).
I started my coals about 1.5 to 2 hours before I am ready to start cooking. You want the coals to be small chucks of hot white embers, i.e. no flames. I stayed with the fire during this burning stage. I read a book while sitting under the shade of a nearby tree. My relaxation stage.
Step 2: Start Cooking
Now that the coals are ready, place your grill and meat in the pit. As you may notice, I do have a little flame on the coals, but they went out once I had it buried.
Step 3: Cover the Pit
Next, place the sheet metal over the pit and start burying it with the soil from the hole. I start by sealing up the edges first, then I cover the top. The soil acts a low heat conductor which keeps the heat inside of the pit.
At this point, I felt the pit could be left on it's own as it was sealed, which reduced the potential of fire escaping out into the field. This choice is up to you. You can always read that book while sitting around.
For my brisket, I left it under for 3 hours to slow cook the meat.
For my chicken, I left it under for 1.5 hours.
This is just the initial cooking stage. Later, I took the meat out of the foil and slow smoked it for more time. More details on that later.
Step 4: Smoking Stage
After the meat has cooked for your preferred time, use the shovel to remove the soil from the top of the metal. Keep the soil piled nicely to one side to be used again.
I removed the meat and grill from the pit. Use appropriate oven gloves or you will regret it rather quickly. Don't ask. :P
Next, I removed the meat from the foil wrapping.
Chances are, your coals are now nearly extinguished. I had this issue twice now, and I think the next time I cook, I will keep an opening on each end of the sheet metal lid to allow some air movement. That will be the next experiment.
I had to restart the coals with some kindling and paper. I burned a couple extra logs to add fresh coals to the pit. Once the wood had burned down (about 30mins), I poured the water off (away from the fire) of the oak discs (in picture). Then I added the wet discs to the coals. The wet discs tend to smolder and produce great smoke.
You can use store bought chips, but I had a saw and wood laying around (No cost!). Be sure to soak your chips overnight in water.
I put the sheet metal back on top, but I did NOT put any soil back on or around the sheet metal. I wanted air inflow and smoke outflow for this stage. I did put a rock on top when was windy, but that did not keep the air from flowing through.
You can stay to monitor the pit or not. Your decision. Finish that book yet??
Brisket: 2 hours
Chicken: 1.5 hours.
Note: make sure the meat is done. Smoke it longer if necessary.
Step 5: Done Stage: Chicken
At the end of 1.5 hours of smoking, I felt the chicken was done. Please use whatever method you like to be confident your chicken is completely cooked!
Here is how it looked:
This chicken was extremely juicy and tender at this point.
Step 6: Done Stage: Brisket
Here is how the brisket looked after 2 hours of smoking:
It was tender and had a great smoke flavor.
Step 7: Seasoning Recipe and Meat Prep
Rub Seasoning Recipe:
3 Tbl Chili Powder
2 Tbl Garlic Powder
1 Tbl Sea Salt
1 Tbl Minced Onion (dry)
1 Tbl Cilantro
1 Tbl Oregano
2 teaspoons Paprika
1 teaspoon Black Pepper (fresh ground)
1 teaspoon Cumin
1 teaspoon Mustard Powder
I put the seasonings into a small food processor and blended on high for a minute or two. This mixed the seasonings well and chopped up the dried minced onions.
The day before cooking, I removed the neck and gizzards from a whole bird purchased at the local grocery store. Then I rinsed and patted it dry. Then, I sprinkled the rub on all sides of the chicken.
Next, I double wrapped the chicken in aluminum foil for the initial cooking stage.
The day before cooking, I cut off much of the exterior fat from the brisket. Then I patted it dry. Next, I sprinkled the rub (liberally) on both sides. Lastly, I double wrapped the brisket in aluminum foil for the initial cooking stage.
Step 8: Final Thoughts
So far this process has worked well for chicken and brisket. I am hoping to try pork meats soon. Hopefully for the holidays, I can smoke a whole turkey underground! Smoked turkey legs anyone??
As for the pit, you can use your imagination to create bigger or even better grills. I can see using a longer piece of sheet metal to make a 6 or 8 foot long (or even longer!) ground pit for cooking way more meat. For my next design, I am considering adding a second section. This section will be for the coals and the primary section for the meat. This would allow me to slow smoke such things as salmon, ham, bacon, etc.
I am contemplating adding some type of air "valve" to the sheet metal lid as well. This would allow me to open the valve for more air inflow, which could keep the coals going longer in the initial cooking stage. I will have to think about that more.
So far the cost for me has been in the meat. Brisket: ~$18 and chicken: ~$5. Thankfully I already had the tools I needed and I had access to a tractor and auger.
And best of all I did not have to buy a metal BBQ grill, which can cost hundreds of dollars!
I think this is a great and fun way to cook, while experimenting with little cost. I can see many opportunities to use this ground pit for all kinds of cooking, including crab/crawdad boils, dutch oven cooking, baking, etc. For me, this what experimenting with food is all about. It is not necessary to spend hundreds of dollars to be creative. I hope you enjoy this and please give me feedback on any of the steps or your personal experience with your ground pit.