bbq pulled pork

Uncle Willie's is a small restaurant in Waterbury, Connecticut that features "real down home pit bbq". It is an unassuming place, located in a strip mall and the decor is nondescript. The food is the real draw there and has garnered it many accolades; among them, Jane and Michael Stern's proclamation "one of America's top ten barbecue restaurants". Those are some big shoes to fill for a bbq joint in the Northeast, but Uncle Willie's not only fills them, but runs triathlons. In addition to their bbq, which is cooked for 12-18 hours over oak and hickory, they offer award-winning fried chicken and volcanic wings. I go there for the "like velvet" pulled pork--deeply flavored, sensual, complex with the mysteries of smoke--it is the stuff that elevates pork to mythical heights.

pulled pork
ancho pomegranate bbq sheet
fried coleslaw
trumpet mushroom fries

The pulled pork that I make at home does not even try to compete with Uncle Willie's, but it is satisfying nonetheless. I rub pork shoulder with a blend of dried herbs and spices and cook it long and slow in the oven. While it is still warm, it lends itself to compression, as I've done here. When tightly wrapped in plastic, the unctuous juices and fat will bind the shreds into a compact shape, which then releases with the pull of a fork.

The sauce is made from a butterscotch and vinegar base, to which I added pomegranate molasses and ground ancho chilies that were reconstituted in OJ. The balance of flavors hit the right notes: caramelized sweetness up front, fruit and acid roll over the tongue, grand finale of heat and spice kick in at the back. I had intended to turn this into a fluid gel, so I added agar, but then decided to present it as a sheet. The agar allows it to be heated.

The fried coleslaw brought in the elements of my favorite way to enjoy pulled pork at Uncle Willie's--the Carolina pork on a bun. Can you guess what makes it work?
I'll be glad to dish if anyone can answer this riddle:

What can you add to something to make it lighter in weight and lesser in mass?

hint: it was added to a component of this dish.