Interesting questions here.
1. Next time you make sausage, separate the fat from the lean and grind them separately (not recommended except for the sake of experimenting). After grinding, fill a cup with fat and another cup with lean. Weigh both cups. What effect overall does a little fat weight have in comparison in non sausage making terms? Meaning in the overall weight of the item? Strictly regarding subcutaneous fat on pork...there just is not that much there. 40 years ago Hams and Picnics would have 1 1/2+ inches of fat arond the muscle. The old guys, Dad/Uncles, would fight if one was taking all the fatty cuts. Over the last 25 years, "The Other White Meat" campaign, instituted by the Pork Producers, has created such lean Pork that 1/2 inch of fat is becoming rare in Supermarkets.
2. Take two steaks of the same weight and thickness. One well marbelled and one very lean. Throw them on a grill with even temps. Which if either cooks faster? Fat is a great insulator and keeps the heat from reaching the protein in the muscle fibers too quickly allowing for Slower cooking. A 2 inch thick Bison Steak will be well done, before 2 inches of A5 Kobe even warms up.
3. The fat cap up or down question has never been answered to my satisfaction in a smoking application. Does it really matter? The so called Basting effect of cooking meat Fat side up, has a much greater impact on the meat at the higher temperatures experienced during Roasting. However there still is some benefit at Smoking temperatures. For instance, while the insulating properties of the fat cap does protect the upper surface of the meat from drying out and allows the slow breakdown of Collagen, the greater affect is the enhancement of the Maillard Reaction. Although a thick solid layer of fat insulates, the Thin liquid fat dripping down the meat conducts the heat to the surface more effectively than the hot Air in the oven or Smoker. This speeds the browning that occurs and enhances the flavor.
4. Scoring the fat cap or removing portions or all of it might allow seasonings to better penetrate, but how does it affect how a well marbelled cut like a butt will cook up moistness wise? Assuming that cook time is not an issue. Or even being able to quantify the fat cap issue in terms of cook time. The Fat melting from the Cap does not really Penetrate the meat. So Marbling will have the greatest impact on the moistness and flavor of the meat. In addition the Low and Slow cooking allows the increased conversion of Collagen and futher enhances moisture. For the low temp cooking of Lean pork cuts like Loin, the most effective use of the Fat Cap would be to Remove it, Cut the Fat into Strips and use Larding Needles to insert the Fat into the lean Muscle.
It would be interesting to see JJ weigh in on these? I hope I was successful at providing some insight...JJ
Good luck and good smoking.
