Prime Rib

Home reconstruction

Two decisions determine whether an expensive joint comes out well, and both are made before it goes in the oven.

Salt it 24 hours ahead, uncovered, in the fridge.

Cook it low and sear it at the end, not the other way round.

Why dry brining beats salting on the day

Salt on the surface draws water out of the meat. That water dissolves the salt, and the resulting brine gets reabsorbed, carrying seasoning well below the surface. It also disrupts proteins so they hold onto moisture during cooking.

A joint salted an hour before cooking is in the worst part of this process — the water has come out and has not gone back in yet, so the surface is wet and the inside is unseasoned.

Either salt it 24 hours ahead, or salt it immediately before it goes in the oven. The middle ground is worse than both.

Uncovered in the fridge, the surface also dries out, and a dry surface is what lets you get a crust later.

Why low-then-sear beats sear-then-low

The classic method blasts the joint at 230°C then drops the heat. The problem is that the outer centimetre or two overcooks while the heat travels inward, so you get a grey, well-done band around a pink middle.

Cooking low — 120°C — means the whole joint climbs in temperature nearly together. Then a short blast at the end browns the outside in minutes, before that heat has time to penetrate.

The result is edge-to-edge pink with a crust on the outside, which is what you paid for.

The thermometer is not optional

Prime rib is judged by internal temperature and nothing else. Time per pound is a rough guide that varies with the joint's shape, its starting temperature and your oven.

• Rare 49°C
• Medium rare 54°C
• Medium 60°C

Pull it 3–4°C below your target. The temperature keeps climbing while it rests.

What you need

• 2.5 kg bone-in prime rib (3 bones)
• 2 tbsp coarse salt
• 1 tbsp black pepper, coarsely ground
• 4 cloves garlic, minced
• 2 tbsp softened butter
• 1 tbsp chopped rosemary
• 1 tbsp chopped thyme

Method

1. A day ahead: pat the joint dry, salt it all over, and leave it uncovered on a rack in the fridge.
2. On the day, take it out 2 hours before cooking. A fridge-cold joint cooks unevenly.
3. Oven to 120°C.
4. Mix the butter, garlic, pepper and herbs and rub it over the joint. Do not add more salt.
5. Onto a rack in a roasting tin, bones down — they act as a natural trivet.
6. Roast to 4°C below your target, roughly 2 to 2.5 hours for medium rare. Start checking at 90 minutes.
7. Out of the oven, tented loosely, for 30 minutes.
8. Oven up to 250°C. Back in for 6–8 minutes to build the crust.
9. Rest 10 more minutes, then carve.

The rest in the middle

Resting before the sear rather than after is deliberate. It lets the temperature even out through the joint, and it means the final blast is doing nothing but browning.

You can hold it at this stage for up to an hour, which is genuinely useful when you are cooking everything else.

Carving

Run a knife along the bones to free the joint, then slice across the grain. Thick slices, about 1.5 cm — thin slices of prime rib lose their heat and their texture.

Storing

Four days in the fridge. Cold rare beef is excellent in sandwiches and reheating it is mostly a way of making it well done.

If you must reheat, 120°C until just warm, or dip slices in hot beef stock for a few seconds.