Basque Country, Spain
The most refined expression of Basque pil-pil technique. Kokotxas are the gelatinous chin flaps cut from just below the salt cod's jaw — approximately 30-40g per fish — and represent the richest concentration of collagen in the animal. Their extreme gelatin content means the pil-pil sauce forms faster than with regular bacalao but also breaks more easily under heat. This is a dish of extreme economy and extreme luxury simultaneously: the least fashionable cut of the least fashionable fish, elevated through technique into one of the Basque Country's defining preparations. Properly executed, the sauce is simultaneously firm and molten, with a trembling quality that reveals its gelatin structure.
Temperature must be held at 60-70°C — lower than for standard bacalao pil-pil. The oil-to-kokotxa ratio must be generous. Never add extra salt — kokotxas from salt cod retain enough salinity even after desalting. The sauce forms through the same circular motion as regular pil-pil but requires more patience. Fresh kokotxas (kokotxas frescas) from live hake are a seasonal alternative and must be salted before cooking.
Fresh kokotxas from merluza (hake) are available in Basque markets in season and considered superior to salt cod kokotxas by many. The finished dish should tremble when the plate is moved. Serve immediately — the emulsion will re-solidify on a cold plate. A small amount of dry white wine added early helps maintain sauce stability.
Cooking at too high a temperature — turns the gelatin rubbery rather than silky. Crowding the cazuela prevents proper emulsification. Expecting the sauce to form quickly — 20-30 minutes of patient circular motion is standard. Confusing kokotxas with regular cod cheeks — the cut and gelatin content are distinct.
The Basque Book by Alexandra Raij