The single most tender muscle on the animal, and the leanest thing in the meat case — under 3% fat. It cooks in twenty minutes and it is ruined in twenty-five, which makes it the cut most often destroyed by people who are being careful.
The psoas major runs along the underside of the spine, inside the ribcage, tucked beneath the loin. It is a hip flexor that is essentially never loaded in a standing animal — it does not bear weight, it does not drive locomotion, and it spends its life protected inside the body cavity. Muscles that do nothing stay fine-grained and accumulate almost no connective tissue, which is why this is the tenderest cut on every four-legged animal that has one. Each pig yields two, each around a pound. One end tapers to a thin tail and the other is a thicker head, which is a real problem: the tail is done several minutes before the head, so it either gets tucked under and tied or cut off and cooked separately. The silverskin — a sheet of tough, non-rendering elastin along one side — must come off, because unlike collagen it does not convert at any temperature and will contract and bow the whole muscle in the pan.
Fine muscle fibers, negligible collagen, and almost no intramuscular fat. That combination means there is nothing buffering the cooking process: no fat rendering, no gelatin forming, no margin. The muscle holds water only as long as the protein matrix does, and past 150°F that matrix contracts hard and wrings out. Because the cut is thin — usually two to three inches across — heat travels to the centre in minutes, so the difference between 140°F and 160°F can be ninety seconds of inattention. Its leanness also means it takes on marinades and cures unusually well, since there's little fat to block penetration, and it benefits more than any other pork cut from a salt treatment before cooking.
The standard because it's fast and it works: hard crust from the pan, gentle even finish in the oven, total time under twenty-five minutes.
HowTrim the silverskin. Salt an hour ahead. Sear all sides in a hot pan, four to five minutes total, then into a 400°F oven for ten to fifteen minutes until 140°F. Rest five. Slice thick against the grain.
Removes the window problem entirely. The muscle cannot overshoot a bath set to its target, which matters more here than on any other cut of pork.
How138-140°F for one to two hours, then dried thoroughly and seared hard for sixty seconds a side. Longer than about four hours and the texture starts going mealy — this is a lean muscle, and extended holds soften it past pleasant.
The taper means the two ends genuinely finish at different times, and evening the thickness is more effective than any temperature technique.
HowEither fold the thin tail back under itself and tie the whole thing at two-inch intervals with butcher's twine, or butterfly the thick head open so both ends are the same depth. Tying also holds the round shape so it browns evenly on all sides.
Small diameter means direct heat can cook it through before the outside burns, which is not true of most roasting cuts.
HowDirect high heat, turned every two minutes for a total of twelve to fifteen. Move to indirect if the exterior is colouring faster than the interior climbs. Pull at 140°F.
This is the cut people reach for when they want something nice, and then treat it like a roast. It has almost no collagen, and collagen is the only thing that makes a long cook worthwhile. In a braise the fibers pass 160°F within twenty minutes, contract, and expel their water into the liquid — and then nothing else happens, because there is no connective tissue left to convert into gelatin and no fat to render. Two hours later you have a pot of flavourful liquid and a piece of meat with the texture of rope. Chuck and shoulder get better over hours because they are paying into an account; tenderloin has no account. The same logic rules out the slow cooker, which is where a great many tenderloins go to die.
Sold two to a package as often as singly, usually a pound to a pound and a quarter each. Look for a uniform pinkish-red colour and avoid anything sitting in a pool of liquid. Check whether the silverskin has been removed — many are sold with it on, and it is worth taking off yourself with a thin flexible knife, sliding the blade underneath and angling slightly upward so you lose as little meat as possible. Do not confuse it with pork loin, which is a much larger, wider roast sold by the same word and cooked completely differently; recipes for one will destroy the other. Avoid pre-marinated tenderloins in plastic — they are typically pumped with a salt-phosphate solution that makes the texture spongy and the flavour flat.
Doneness: Pull at 138-140°F, rest five minutes, serve at 145°F. Sous vide 138-140°F. It should be clearly pink through the centre. Above 150°F it is unrecoverable.
Completely different muscles that share a name and nothing else. Pork loin is a large, wide roast from the top of the back — three to five pounds, often sold with a fat cap, roasted for an hour or more. Tenderloin is a thin cylinder from under the spine, about a pound, cooked in twenty minutes. Using a loin recipe on a tenderloin overcooks it by a factor of three. Read the package carefully; the words are nearly identical and the outcomes are not.
Yes. Silverskin is elastin, not collagen, and the distinction matters — collagen hydrolyzes into gelatin with time and heat, elastin does not convert at any temperature you will ever reach in a kitchen. Left on, it stays as a tough band, and worse, it contracts as it heats and bows the tenderloin into a curve so it cooks unevenly. It takes ninety seconds to remove.
Yes, and it's one of the better uses for the cut, because the stuffing adds moisture the muscle doesn't have. Butterfly it lengthwise, pound to an even half inch, fill, roll and tie. Cook to the same 140°F — but measure in the meat, not the stuffing, and keep the filling to things that don't need cooking themselves, since twenty minutes won't do it.