Bacalhau — Desalting & Olive-Oil Confit

What It Is

Salt cod is cured rock-hard and intensely saline; it must be rehydrated and desalted before cooking. The optional second move — confiting the desalted loin in olive oil at low temperature instead of boiling it — is the single biggest upgrade to texture, taking it from flaky-but-dry to silky.

Why It Matters for Flavour

Desalting is not just salt removal; it rehydrates the proteins and restores a texture no fresh cod can match — denser, more layered, cleanly flaking. Get it wrong in either direction and the dish fails: under-desalted is inedibly salty, over-desalted is bland and mushy. Confit matters because cod's loose flake overcooks and dries the instant it passes ~65 °C in water; held in oil at 65–70 °C, it sets gently, the flakes separate cleanly rather than falling apart, and the flesh stays moist and glossy. Confit mercilessly exposes cod quality, so it's also where good fish pays off.

How to Execute

Desalt: rinse off surface salt, submerge in cold water, and keep it in the fridge (warmth invites spoilage and uneven results). Change the water every 6–8 h. Time by thickness: thin pieces ~24 h / 3 changes; thick 2–3 cm loins 36–48 h / 4–5 changes. Taste a sliver before you stop — it should read as pleasantly mild, faintly saline, not aggressive. A pro trick for confit: add a splash of milk to the final water change to soften the skin collagen for an even silkier result.

Confit: dry the loins thoroughly (surface moisture splatters and blocks oil contact), rest 15–20 min at room temp, then submerge in olive oil held at 65–70 °C for 12–20 min depending on thickness — use a thermometer; the oil should barely shimmer with no real bubbling. For à lagareiro specifically, you then crisp it briefly under high heat with the smashed potatoes and garlic, but the confit gives you the moist interior first.

Common Mistakes

• Desalting at room temperature → uneven, risks spoilage over a 2-day soak.
• Not tasting before cooking → the only reliable check; thickness varies.
• Boiling instead of confiting → dry, falling-apart flakes.
• Wet loin into the oil → splatter and steaming instead of gentle poaching.
• Oil too hot (>75 °C) → you've just boiled it in fat; collagen seizes, flesh dries.

How to Tell When You've Nailed It

Raw-desalted: a tasted sliver is mild with a whisper of salt. Confited: the loin's large flakes separate cleanly under gentle pressure into glossy, translucent-edged leaves, moist all the way through, with no chalky dry centre and no salty slap.