Home › The World's Kitchen › Potage, Catherine
Potage, Catherine
Place in a saucepan a pound of fresh fish bones, one sliced carrot, one sliced onion, two branches celery, two branches parsley, one sprig thyme, one bay leaf and one clove. Moisten with three quarts water, season with two teaspoons salt, and let boil for one hour. Mix in a saucepan one ounce butter with two ounces flour. Strain the fish broth into this pan, mix on the fire until it comes to a boil, and let slowly boil for thirty minutes. Shell a pint of cooked shrimps, cut half of them in three pieces each and keep on a plate till required.
Place the uncut shrimps and shells in a mortar and pound to a smooth paste, then add it to the soup. Mix well, and let boil for fifteen minutes. Strain the soup through a sieve into a basin, then through cheesecloth into another saucepan, pour in one gill milk and same quantity cream, mix well and let boil for five minutes. Add the shrimps, with three tablespoons cooked, green peas and saltspoon cayenne pepper, boil for three minutes, pour into a tureen and serve.
A classic shrimp bisque built on a fish fumet, thickened with a roux and enriched with pounded shrimp shells. The shells are the whole point of the dish, so do not be tempted to skip them.
- The hinge: pound the shells, then strain twiceMuch of the flavor and the pink color come from crushing the shells into the soup. A food processor does the work of the mortar in under a minute; the double straining (sieve, then cheesecloth) is what keeps grit and shell splinters out of the finished bisque.
- Gill and saltspoonA gill is half a cup, so the finish is 1/2 cup milk and 1/2 cup cream. A saltspoon is about 1/4 teaspoon — with cayenne, start with a pinch and correct at the end.
- Fish bonesAsk at a fish counter for the frames of any lean white fish — flounder, sole, cod, halibut. Avoid salmon, mackerel and other oily fish, which turn a fumet muddy. Rinse the bones well and pull out any dark viscera or gills.
- An hour is too long for fish stockModern practice stops a fish fumet at 20 to 30 minutes; past that the bones give up bitterness and glue rather than flavor. Three quarts of water will still reduce usefully in that time, and you can simmer the strained broth down further if you want it stronger.
- The roux and its 30 minutesOne ounce butter (2 tablespoons) to two ounces flour (about 1/2 cup) is a stiff, flour-heavy paste by current standards. The long slow boil is there to cook out the raw starch taste; stir the bottom often, and expect a soup that coats a spoon fairly heavily. Thin with extra broth if it tightens too much.
- Cooked shrimpA pint of cooked shrimp in the shell runs somewhere between three-quarters of a pound and a pound depending on size; shell-on raw shrimp poached briefly in the fumet will give better texture than pre-cooked. Reserve half, cut in three, for garnish and keep them out of the long boiling.
- Don't boil the cream stage hardThe final five minutes should be a bare simmer. A rolling boil after the dairy goes in risks curdling, and the reserved shrimp pieces need only a minute or two to heat through — three minutes at a hard boil makes them rubbery.
- YieldAs written this makes roughly two quarts after reduction and straining: six to eight first-course servings.
Bisques of this kind — shellfish pounded shell and all, then strained and finished with cream — are the French restaurant tradition that Alexander Filippini and his contemporaries brought wholesale into American hotel cooking, and The International Cook Book is full of them, arranged alphabetically by recipe name. Naming a soup or garnish after a person (Catherine, Clémentine, Suzanne) was standard nineteenth-century kitchen shorthand, and it is often said to have saved a cook from writing out "with diced shrimp and green peas" every time; the names traveled from one printed menu to the next long after anyone remembered whether a Catherine ever existed. The pounding of shells in a mortar, tedious as it is, was also the era's usual way to extract that flavor; the technique survives intact in modern bisque, only the tool has changed.