First of all, thanks!
I would make more pulled pork than that, make it ahead, and freeze it in about 5 pound amounts (about 18 sandwich) in the oversize freezer baggies (I think they are 3 gallons) in thin, flat layers. I would make 2 extra baggies for up to 140. Then on the day of, you can start with 100 people worth and pull out the extra baggies as needed for appetite. Thaw the main amount in the refrigerator 18-24 hours (1-2 nights) and the quickie bags, in a roaster or in a roasting pan in the oven at about 400.
Here is the recipe you were looking for:
As for pulled pork, here is a recipe for 8 pounds from a Carolina cook that is about as good as you can find. Note that this amount of sauce is only for 8 pounds meat, you will need 4 times as much for your 32 pounds.
2 pork butts, 3 to 4 pounds each, untrimmed (can sub shoulders)
Sauce:
1/3 cup honey
1/3 cup molasses
1 head garlic, broken into unpeeled cloves
2 Tb. whole cumin seeds
3 Tb. whole coriander seeds
1 Tb. whole black peppercorns
8 small dried red chiles
2 bay leaves
3 Tb. tomato paste
3 15-oz. cans diced tomatoes, with juice
1 quart distilled white vinegar
4 cups water
1/4 cup salt
Combine the honey, molasses, garlic, cumin, coriander, peppercorns, chiles and bay leaves in a large stockpot, over medium-low heat. Cook for 30 minutes, stirring occasionally. The garlic will darken, and the mixture will be very thick and fragrant. Add the tomato paste and tomatoes; cook for 15 minutes, stirring frequently. Stir in the vinegar, water and salt. The sauce should be thin. Simmer, uncovered, for at least 2 hours, stirring occasionally.
Set aside half the sauce for marinating the pork. Let the remaining sauce cool and fish out any large pieces of garlic peel. Puree the remaining sauce in a blender (some spices will remain whole). The sauce should be rather watery and look like a brothy tomato soup.
One or two days before cooking (much preferably two), put the pork in a container just large enough to hold it and deep enough for the reserved sauce to cover it. Cover the container and refrigerate, turning the pork half-way through the marinating period.
At this point, you're finally ready to cook the pork. I have tried this in a number of methods and variations, but have settled on a two-step process that works great. I cook half-way in the oven (before basting is necessary and saving propane) and half-way on a grill using indirect heat (making it easier to baste and adding the barbecue flavor you need). The formula is 2 hours per pound (or cooked to an internal temperature between 150 to 160 degrees).
Pre-heat the oven to 200 degrees. Put the pork, fat side up, on a rack in a roasting pan. Leave in oven three hours (for six pounds) or four hours (for eight pounds). Remove to pre-heated grill, but with low, indirect heat (should be about the same 200 degrees as your oven). Baste with the pureed sauce every 30 minutes, until done, turning once (this second half of cooking will take as long as the first, if your grill is correctly regulated). Let the pork cool.
Chop and shred the pork. You can either slice it or pull it apart with your fingers (thus the name, "pulled pork"). For slicing, cut the pork across the grain, in half-inch slices. For pulling, start pulling at the meat with a fork, then attack with your fingers. Discard any unrendered fat.
With a large knife, roughly chop the pork coarse. Put the chopped pork in a large bowl with some more of the pureed sauce; the amount is up to you (I'd go a little at a time, and test along the way). Serve the pork warm (no problem with a microwave; it's plenty juicy -- if you cooked it right) with a little more sauce on the side, for your bolder eaters.
It's a lot of work and that's why I usually go 8 pounds, so I can freeze half and eat it a few months from now. I figure if I'm going to this much trouble, I might as well make as much as the sauce can handle (8 pounds being the top end). Enjoy and tell any friends in Asheville or Memphis that you've got 'em beat.
**MID-SOUTH CAROLINA MUSTARD SAUCE***
1 cup cider vinegar
6 tablespoons Dijon mustard
2 tablespoons maple syrup or honey
4 teaspoons Worcestershire sauce
1 teaspoon hot red pepper sauce
1 cup vegetable oil
2 teaspoons salt
ground black pepper
And...Here's a great spicy chili rub to use before cooking...
***SPICY CHILLI RUB***
1 tablespoon ground black pepper
2 teaspoons cayenne pepper
2 tablespoons chili powder
2 tablespoons ground cumin
2 tablespoons brown sugar
1 tablespoon ground oregano
4 tablespoons paprika
2 tablespoons salt
1 tablespoon granulated sugar
1 tablespoon white pepper
Enjoy....
