How to desalt bacalhau correctly — A guide for professionals

Why proper desalting is a technical operation, not a routine Desalting dried salted cod is often treated as a trivial step. In professional practice, it is a critical operation that determines the final salt content, texture, yield and, ultimately, dish quality. Insufficient desalting produces an excessively salty product; over-desalting results in a disintegrated texture and loss of flavour. This guide establishes the correct technical parameters by grade. Fundamental principles before you begin Regardless of grade, three rules are non-negotiable. First, temperature: desalting must take place in a refrigerated environment (0–4 °C). Above 8 °C, bacterial activity increases sharply and the outer layers of the fish soften unevenly, compromising texture. Second, immersion: the piece must be fully submerged and weighted if necessary to prevent the top surface drying out and developing an irregular salt gradient. Third, water volume: use a minimum ratio of 3:1 (three litres of water per kilo of salted fish). Recommended times by grade Small grade (under 500 g whole): 24–36 hours, 2 water changes. Corrente- grade (500 g–1 kg): 36–48 hours, 3 water changes. Corrente+ / Crescido (1–2 kg): 48–60 hours, 4–5 water changes. Especial (2–3 kg): 60–72 hours, 5–6 water changes. Especial Jumbo (over 3 kg): 72–96 hours, 6–8 water changes. These times assume the piece has been cut or split. Whole unsplit fish require 20–30% additional time. Water-change frequency and the critical 6-hour rule The first water change should occur after the first 6–8 hours — this initial change removes the largest concentration of salt released from the surface. Subsequent changes every 8–12 hours maintain a low-salt water gradient that favours continued diffusion. Changing water less frequently does not speed up desalting; it slows it down, as the concentration gradient between the fish and the water equalises. Temperature and its effect on texture Desalting at room temperature (18–22 °C) accelerates the process but causes the outer layers to over-hydrate while the centre remains under-hydrated. The result is uneven texture in cooking. Refrigerated desalting (0–4 °C) is slower but produces a homogeneous result. For HORECA operations that need to shorten the process, 8–10 °C is an acceptable intermediate — but never above this. How to check whether desalting is complete The professional method is simple: cut a small piece from the thickest part and taste it raw. The salt level should be perceptible but not dominant — similar to a well-seasoned dish. Alternatively, use a calibrated salt meter (salinometer) to measure the brine: a final reading of under 1.5% NaCl in the soaking water indicates the process is near complete. Visual check: the flesh should be flexible and uniformly white-beige throughout. Common professional errors Using warm or hot water to accelerate the process: destroys texture and promotes bacterial growth. Changing all the water at once with ice-cold water: thermal shock causes the surface to contract, trapping salt in the centre. Desalting in too small a container: limits water volume and equalises concentration gradient prematurely. Leaving the skin upward: salt drains down by gravity — skin should always be upward to allow salt to drain away from the flesh.