We decided to go the spit-roast route, and rather than buy a commercial rig, we decided to design a spit and have it made for us locally. My dad and I used Hugh Fearnley-Whittingstall's pictures in the River Cottage Meat Book as a guide, and drafted some plans. Here is the result.
The most salient feature of this design is its dual fire pits. The idea is to make all the heat indirect, which minimizes the chances of burning and also makes it easier to add large quantities of fuel at a time.
the pit
The pits are approximately 6 x 2 x 1 ft. The top is stainless steel, while the bottom is not, but has been painted with some sort of heat resistant BBQ paint. There's also a cross bar for support, and the whole thing can be taken apart (you can see the bolts holding the structure together above). If I had to redo-it, I would put another set of nuts on the vertical face, but the cross bars do a great job stabilizing the whole thing so it's a minor point. The bottom and inside faces are made of mesh to keep airflow high, while the sides as solid to redirect heat.
the crank
This is the crank. We left room at the other end to attach a motor, but I insisted there at least be a manual option in case the motor breaks down. The handle is made of teflon, so it shouldn't burn or melt. It locks in 8 different positions with the help of the large stainless steel disk and locking pin (the t-shaped thing at the bottom). To rotate the shaft, simply remove the pin and crank. The shaft is set in two pilot bearings, which rotate incredibly smoothly.
The barely visible hooks in this picture are to adjust height. The pilot bearings are bolted on to an inverted "U", which engages the hooks. To adjust the height two people are needed to lift the bar and set it onto the desired hooks. Not the most fun job when the fire is roaring, but I've found height adjustments not very necessary (it's much easier to simply modulate the fire).
Before the wedding, we thought it would be a good idea to put the spit through its paces, and it just so happened that we had another occasion to celebrate! My family is in the oyster business, and we just opened NB's first commercial shellfish hatchery. The grand opening was last weekend, and after the press conference, I ran off to my aunt's house to start a fire.
the fire
This thing cranks out epic heat. For the first hour or so we just tried to built up a good amount of ambers. The aluminium foil is there because my aunt didn't want me to mess up her tiles, although in retrospect putting little wood weights there was not a great idea (it all basically vaporized).
For our inaugural run, we decided to roast some lamb (40lb) and some chickens (10lb each). The shaft, is quite large (1.5 in square), so getting it through was a bit of a challenge. I've heard some people use different size shafts depending on what they are roasting, we managed to fit everything on there. I simply rubbed the meat with some olive oil, salt, and pepper.
the meat
You can see that the meat is raised fairly high above the pits, even on the lowest setting. We burned about 6 cubic feet of wood every half an hour throughout the process (over the 3.5 hour cook time we burned about a quarter of a cord of mostly maple and beech). I was turning it randomly (more erratically as I drank more), but I would guess it amounted to a quarter turn every 20min.
nearing completion
At this stage I was putting on wood towards the ends only, for two reasons. One was to avoid overcooking the ribs (which are much thinner), and also, to cook the chicken well. I was quite surprised at how evenly everything cooked. After about 3.5 hours, we decided to pull everything off. By this time, the chickens were at ~160F, and the lamb was ~150F, with a bit color left in the thickest parts.
done
carving
I was convinced the lamb was going to be dry and overcooked, but my relatives insisted the meat be well done (I would normally pull it off closer to 120-125F if I was roasting a joint at home). I was wrong. Everything was delicious and juicy owing to the fact that the fat and collagen managed to break down. Not bad for a first try!
It was really great to have a chance to do a test run before the big day in 3 weeks, I'm planning on roughly doubling the cooking time for a 90 lb pig (8-9 hours).
