The crux of Blumenthal's patty crafting method comes during the grinding process. As the meat leaves the grinder, it will be forced out in long strands.
Instead of letting these fall into a pile, you'll need to guide the strands and lay them down on a sheet of plastic wrap, ensuring that they don't tangle.
This is a two-person job that requires one person to run the grinder and another to cradle the ground meat. This extra effort will create a firm and delicious burger patty.
Keeping each strand in alignment will prevent excessive binding. Then, roll the entire mixture into the shape of a log by gently enveloping it in the plastic wrap.
After refrigeration, use a sharp knife to slice the tube crosswise into patty-sized sections. When you look at a cross-section, the strands should run vertically in each burger.
Blumenthal uses a blend of 50% chuck, 25% short rib, and 25% brisket. He notes that the brisket gives a "buttery-type fat" while the short rib adds a "wonderful, nutty flavor."