The perfect weight for Whole Hog BBQ
The largest hog I've ever cooked weighed 220lbs. Hogs I cook at home tend to be within the 125lb ball park. I wouldn't really bother with pigs that weigh under 75lbs, believing those to be better suited for spit roasting rather than slow smoking.
Now most people are not going to determine how big of a hog they're gonna buy based off optimal results. It's more a function of how many people you're gonna feed. But it is pretty well noted that some pitmasters have a preference for what size hog they're gonna use.
In North Carolina, hog joints tend to prefer to cook in the 150lb range.They'll go south of that range if it's exceptionally busy. At this size the pitmasters get a bit more sleep and have to worry less about grease fires.
Here's 2 opinions on how big your pig should be :
Danny Hurdle the pitmaster over at Carolina Pit Barbecue in Ashburn, VA, a manwhose opinion I deeply respect, says
The pig can’t weigh an ounce over 140 pounds. Any bigger than that, and he’s not a pig, he’s a hog, and all you’re cooking is grease.
Myron Mixon who has won multiple championships in Whole hog notes in his book
I like cooking the big ones the best (North of 180-200lbs), because they've got the most amount of meat on them and can serve a huge crowd. Now some 'cue cookers may tell you that smaller is better because it's easier to handle, but I don't truck with that. The quality of the meat on a smaller hog is no different than on a bigger one, and if you're going to go to all the trouble to smoke a whole hog, then you might as well get as much as you can for your efforts.
Taste itself is subjective. Me personally I like to cook the biggest hog I can because the larger fatback protects the backloins better. Logistics-wise it's better to cook a hog that's an even 100lbs (+/- 20lbs). When you get hogs that are larger than 150lbs, there's an increase risk of grease fires as the larger beast drips more fat. A proper drainage system will help but the threat is always there.
If it's your first hog I'd recommend starting at 75 lbs. There's really no reason to smoke a hog smaller than that. There's not much flavor developed and expect your pig to shrink by 60%. And please please do not smoke a 20-30lb pig. That's just tragic. You will literally get less meat out of the animal than a turkey. Plus butchers hate you. Pigs at this size are a pain to source and they charge you accordingly. I've seen prices almost double for someone looking to order a sub-50lb pig.