The Science Behind Pan Heating: Understanding Hot Spots

Heating a pan is an important step in the cooking process. A hot pan is necessary for achieving browning without overcooking. For example, if you start cooking a steak in a cold pan, it will be cooked past well-done before the outside has a chance to brown. A hot pan is also important for searing meat or vegetables to create a crispy exterior.

There are several ways to test if a pan is hot enough. One way is to add a few drops of water to the pan. If the water sizzles and evaporates within a couple of seconds, the pan is hot enough for sautéing. If the water dances on the surface of the pan, it is hot enough for searing. Another way to test if a pan is hot enough is to add oil. If the oil shimmers or glistens when you tilt the pan, it is hot enough.

The Leidenfrost effect

The phenomenon where a pan gets so hot that water forms a steam layer underneath itself is called the Leidenfrost effect.

Searing

To sear meat effectively, it is important to ensure that the pan is hot before adding the meat. This allows the meat to develop a rich brown crust on its surface, enhancing the flavour of the dish. The Maillard reaction, a chemical reaction between amino acids and sugars, is responsible for the desirable flavours created during searing. While searing does result in moisture loss, it is still a valuable technique for improving the taste and texture of the food.

When searing meat, it is recommended to let the meat reach room temperature before cooking. This helps the meat relax and allows its natural moisture to reabsorb into the muscle fibres. Additionally, seasoning the meat with salt (and optionally, pepper) enhances the flavour of the crust. It is crucial to ensure that the meat's surface is dry and free of water, as moisture can interfere with the browning process.

The pan should be heated to a high temperature, and the addition of oil or fat is essential to create a non-stick surface. The type of oil used is important, as some oils, like olive oil, have a low smoke point and are not suitable for searing. Once the pan is hot, the meat is placed inside, typically with the fattiest side down, and left undisturbed for a few minutes to form a crust.

Sauteing

Sautéing is a cooking technique that uses a small amount of fat to cook food quickly in a hot pan. The word 'sauté' comes from the French word for 'jump', referring to the motion of making the food flip in the pan so that it doesn't sit in one spot for too long. Sautéing is best done with a shallow pan with a wide flat base and low sides, to maximise the surface area available for heating. The pan should be hot over high heat before adding the fat, and the fat should be heated up before adding the food. The food should be cut into small, even pieces to ensure quick and even browning. The food is then left to brown, being turned or tossed frequently for even cooking.

Sautéing is a quick and versatile method of cooking, mainly used for vegetables, but it can also be used for meat, chicken, or fish. It is important not to overcrowd the pan, as this will cause the food to steam instead of brown. The food should be in an even layer across the bottom of the pan, with minimal overlap. If you are cooking a large quantity of food, it is better to work in batches than trying to sauté everything at once.

The type of oil used for sautéing is also important. A high smoke point/neutral-flavoured oil such as grapeseed, avocado, canola, or vegetable oil is recommended. Olive oil should be avoided, as it burns at high temperatures and can make the food taste bitter. Only enough fat to lightly coat the bottom of the pan is needed; too much fat will cause the food to fry.

When seasoning with salt and pepper, it is best to do so at the beginning of the cooking process and throughout as necessary. Fresh herbs should be added at the end of the cooking process. If your food starts to caramelise too quickly, you can add a few tablespoons of water to the pan to cool it down and transfer more flavour to your food. This is called "deglazing". Generally, you deglaze with wine, spirits, citrus/vinegar, or water.

Stir-frying

To stir-fry, first heat the wok to a high temperature. Just as the wok starts to smoke, add a small amount of cooking oil down its side—a traditional Chinese expression for this step is "hot wok, cold oil". Then, add dry seasonings like ginger, garlic, scallions, or shallots, and toss them with a spatula until fragrant. Next, add the ingredients that take the longest to cook, such as meat or tofu, followed by combinations of soy sauce, vinegar, wine, salt, or sugar, and thickeners.

Browning

Before browning, the surface moisture of the ingredient should be removed by patting it with a paper towel. This is because any moisture left on the ingredient can turn into steam, preventing the crust from becoming crispy. Additionally, the pan should not be overloaded as this can also compromise the browning process.

Frequently asked questions