Poaching is a wet-heat cooking method whereby food is submerged in liquid and gently cooked. Shallow-poaching is a subtype of poaching in which the food is only partially
Poaching is a wet-heat cooking method whereby food is submerged in liquid and gently cooked. Shallow-poaching is a subtype of poaching in which the food is only partially submerged.
Heat is transferred to the food via conduction, (direct contact with the hot liquid), and convection, (the movement of the fluid medium).
The difference between poaching, simmering, and boiling is the temperature of the liquid. Poaching is from 160 to 185 degrees, simmering is beyond 185, and boiling is when you obviously achieve a full boil.
These temperature differences are not arbitrary and have significant ramifications for the food to be cooked. The hotter the fluid, the more destructive it's force, not only from the higher temperature but the increased turbulence as well.
You would never put a fragile piece of fish into boiling water. The heat and agitation would disintegrate it. Therefore, the temperature of the poaching liquid should be checked during cooking with an instant read thermometer. As stated, poaching is gentle cooking.
The surface of the water should only be shimmering and devoid of any roiling bubbles. The foods best suited for poaching are naturally tender and delicate, e.g., fish, eggs, chicken and fruits.
Common fluids used for poaching include water, stock, wine and court-bouillon, a broth made from water, wine, vinegar and/or citrus juice, aromatics and herbs. Sometimes the poaching liquid is employed only for cooking and sometimes the leftover liquid is incorporated into a sauce.
Poaching liquids used only for cooking should be amply seasoned. All wet-heat cooking methods leach some flavor from the food. This can be offset by a flavorful poaching liquid.
If the poaching liquid is to be used as a sauce, you may need to reduce it further once the food has finished cooking. This will depend on how much liquid you started with, how much is left over after poaching, and the target concentration of the sauce.
If further reduction is required, place the food in another container with some of the liquid to prevent it from drying out while you prepare the sauce.
Poaching can be done with or without a lid. Covering the pan will increase the temperature of the poaching liquid. Thus, you will need to decrease the heat source accordingly to maintain the proper temperature.
The lid will also inhibit the evaporation of the poaching liquid. This is a moot point if the liquid is to be used only for cooking and not for a sauce.
But if the liquid is to become a sauce, and if reduction is required, the lid will thwart that effort, unless your plan is to do all the reducing after the item is cooked.
For example, if you have just enough liquid to cover the food, and you wish to keep the food submerged throughout the cooking, then you would employ a lid and reduce the liquid afterwards.
SHALLOW-POACHED SEA BASS
I strongly recommend you use a rather thick piece of fish. Standard fish fillets are too thin to use a thermometer and can be easily overcooked if you lack experience judging their dinners from appearance alone.
With a good sized fillet and a thermometer the guesswork is eliminated and the fish can be cooked precisely. Overcooking will cause it to dry out and crumble.
POACHED PEARS IN RED WINE