Brisket Flat

The brisket flat (also called the "first cut") is the larger of the two muscles in a whole packer brisket. It's the pectoralis profundus — a long, relatively thin, rectangular muscle covered by the fat cap on one side.

Characteristics: - Makes up about 60-65% of the whole packer weight - Leaner than the point, with less intramuscular fat - Relatively uniform thickness (tapers at one end) - Produces the classic, clean, uniform brisket slices - More prone to drying out during cooking

Why the Flat Is Hard to Cook: The flat has a narrow window between "done" and "dry." It needs to reach 200-205°F internal for the collagen to fully convert to gelatin, but with less fat to protect it, the muscle fibers can tighten and squeeze out moisture at those temperatures. This is why grade matters so much for brisket — a Prime flat with good marbling stays moist at 203°F. A Select flat at the same temperature is cardboard.

Buying Just the Flat: You can buy separated flats at many grocery stores. If you do, know that it's significantly harder to cook well without the point's insulation. Choose the highest grade available, don't over-trim, wrap earlier (155-160°F), and rest longer (minimum 2 hours).

Slicing the Flat: Always slice against the grain. The grain in the flat runs lengthwise along the muscle. Cut pencil-width slices (about 1/4 inch) across the grain. A sharp, long slicing knife is essential — a dull knife tears the meat and releases juice.

The flat is what most people picture when they think of sliced brisket. It's beautiful, clean, and satisfying when done right — but it demands more precision than the forgiving, fatty point.