Lobster bisque — one of the most labour-intensive preparations in the classical French repertoire — achieves its characteristic rich colour and deep, sweet-savoury flavour through a process of crustacean shell caramelisation, cognac flambé, cream reduction, and final straining. Every step extracts a specific component: the shell caramelisation provides the colour and the sweet depth; the cognac provides aromatic depth and the flambé's rapid alcohol combustion produces specific aromatic compounds; the cream binds and rounds the flavour.
- **Shell caramelisation:** The lobster shells (and heads) are crushed and sautéed in butter and oil at high heat until they turn deep orange-red — the Maillard reactions on the shell surface proteins and the carotenoid pigments (astaxanthin) release into the fat. - **Mirepoix:** Added and sweated in the shell-flavoured fat. - **Tomato paste:** Added and cooked until it caramelises on the pan surface. - **Cognac flambé:** The alcohol ignites briefly — the rapid combustion produces specific aromatic compounds from the alcohol's partial combustion. - **The long simmer:** In fish stock, cream, and white wine — 45–60 minutes for the shell's residual protein to fully extract. - **Straining and blending:** The shells are removed; the bisque is blended (or the shells blended with the liquid and then strained) for maximum extraction. - **Cream reduction:** The final consistency adjustment.
The Complete Robuchon