Oil-poach
Oil-poaching cooks food gently submerged in warm oil, well below frying heat. Fish turns silky and moist, and the oil can be reused for flavor.
Also called Oil poaching, Oil-poached, Poached in oil.
To oil-poach is to cook food fully submerged in oil kept at a low, steady temperature, usually 50 to 95°C (120 to 200°F). The oil never gets hot enough to fry or brown the food. It is used most for fish such as salmon, cod, halibut and tuna, which come out evenly cooked, soft and moist. The method is close to a confit, but quicker and usually for delicate food.
How to do it
- Take the fish out of the fridge 15 to 20 minutes before you cook it. Season it with salt.
- Choose a small pan that fits the fillets snugly, so you need less oil.
- Pour in a mild oil, such as olive oil or a mix of olive and neutral oil, deep enough to cover the fish. Add aromatics such as garlic, citrus peel, herbs or chiles.
- Heat over low heat with a thermometer in the oil. For salmon, aim for about 55 to 60°C (130 to 140°F). For firm white fish, aim for about 65 to 75°C (150 to 165°F).
- Lower in the fish. Keep the oil at a steady temperature; move the pan on and off the heat as needed.
- Cook for 10 to 25 minutes depending on thickness and oil temperature.
- Lift out with a slotted spatula and let the oil drip off.
How to tell it is done
The flesh changes from translucent to just opaque and flakes when pressed gently. In the thickest part, the fish reaches the temperature you want. For fully cooked fish, USDA guidance is 63°C (145°F). Lower temperatures give a softer, more translucent texture.
Why it works
Oil holds heat steadily and surrounds the food, like water when you poach. Unlike water, it does not draw out the fish's flavor or soluble proteins, so the fish stays moist and tastes of itself. The low heat leaves almost no overcooked edge.
Common mistakes
- Oil that creeps too hot. Small bubbles mean it is frying. Turn the heat down.
- No thermometer. You cannot judge the temperature by eye.
- A wide pan. You need much more oil to cover the food.
- Keeping used oil at room temperature. Strain it, refrigerate it, and use it within a few days for dressings or cooking.
In recipes
"Olive oil poached salmon" and "tuna confit" both describe this method.
Related terms
- ConfitConfit is food cooked slowly in fat at a low heat until meltingly tender, then often stored in that fat. Duck confit and garlic confit are the classics.
- PoachPoaching cooks food gently in liquid kept just below a simmer, around 70 to 85°C (160 to 185°F). Eggs, fish, chicken and fruit stay tender and moist.
- ThermometerA kitchen thermometer checks the heat of meat, oil, sugar and your oven, so food is safe and cooked how you want. Here is which type to use and how.
- FilletA fillet is a boneless piece of fish or meat, and to fillet is to cut that piece away from the bones. Here is how to fillet a round fish cleanly.
- Sous videSous vide cooks vacuum-sealed food in a water bath held at an exact temperature, so meat and fish cook evenly edge to edge and cannot overshoot.