The regional table / South Carolina
Midlands Pulled Pork with Yellow Mustard Sauce
Cross into the middle of South Carolina and the sauce on the pork turns yellow, and everyone there can tell you the county line where it happens.
The South Carolina Encyclopedia entry on barbecue, written by the geographer Charles F. Kovacik, sets out the state as a sauce map: at least four basic types, watery pepper-and-vinegar in the Pee Dee, peppery tomato or milder ketchup up in the Savannah River country and the upstate, and a yellow-mustard-based sauce favoured in the Midlands. It also describes the pit the old houses cooked on — a rectangular cement block box about three feet high with iron rods across the narrow width, hickory or oak coals on the floor and openings at ground level for refuelling and air — and notes that the whole hog belongs to the coastal plain, while shoulders, hams and Boston butts are what the Piedmont cooks.
What that entry never says is why the Midlands sauce is yellow, and the usual answer deserves more care than it gets. German settlement of the Midlands is documented and not in doubt: Bernheim's 1872 history of the German settlements and the Lutheran church in the Carolinas traces the Saxe-Gotha township, now Lexington County, to Germans on the ground by 1737, citing the Council Journals and a petition of May 1742 from the Gieger, Shalling, Kinsler and Bieman families for the bounty owed to settlers who had been there since. The leap from that to the mustard is where the record thins. Robert F. Moss, writing in Barbecue Lover's The Carolinas, lays out the case — the Dutch Fork where the Broad and Saluda meet, and the run of German surnames over Midlands barbecue: Hite, Bessinger, Dukes, Shealy, Lever, Price — and then knocks it down, pointing out that the same German ancestry is credited with the vinegar sauce of the North Carolina Piedmont in Gary Freeze's German conjecture, and with the sauceless beef of Texas. An explanation that produces three opposite traditions explains none of them. The Germans were there; whether the mustard came with them is not something any document I could open will confirm.
Why this version works
275°F for the whole run. Pork shoulder is worked muscle full of collagen, and collagen turns to gelatin slowly between about 160°F and 200°F. A low oven keeps the meat in that band for hours, which is the entire trick; hotter and faster gives you a roast that slices but will not pull.
Sauce goes on at the end. Mustard and sugar in a 275°F oven for seven hours burn to a bitter crust. The rub does the seasoning during the cook; the sauce arrives after the meat is pulled, when it can taste of mustard rather than of scorch.
Cook to feel, not to the clock. A butt is done at roughly 203°F, but the real test is a skewer sliding in with no resistance anywhere. Two shoulders of the same weight can differ by an hour, and pulling one out early is the single most common way this dish is ruined.
The sauce is cooked, not stirred. Raw yellow mustard whisked with vinegar tastes sharp and thin on hot pork. Ten minutes at a simmer knocks the rasp off the mustard, dissolves the sugar properly and thickens the sauce enough to cling instead of running off the meat into the bottom of the pan.