Cooking Oil Sticking To Pan: What's The Reason?

Oil is an essential ingredient in cooking, but it can be a pain to clean up, especially when it sticks to your pan. This often happens when oil is heated above its smoke point, causing its triglycerides to decompose into free fatty acids, which form a type of resin that won't dissolve in water. This resin can be difficult to remove, requiring special cleaning techniques and products. However, there are ways to prevent oil from sticking to your pan in the first place. This includes ensuring your pan is hot before adding oil, drying your food before cooking, and maintaining your pan by seasoning it with a neutral, high-smoke-point oil.

Oil heated above its smoke point can cause sticking

Oil has a smoke point, which is the temperature at which it breaks down and fails as a lubricant. When oil is heated past its smoke point, it starts to break down and release free radicals and a substance called acrolein, which gives burnt foods their acrid flavour and aroma.

The smoke point of oils varies depending on their level of refinement, the seed variety, and even the climate and weather during the plant's growing season. Virgin or raw oils have many compounds that contribute to flavour and aroma, but they tend to burn more easily. As oils are refined, these compounds fall out, raising the smoke point but reducing the flavour.

When oil is heated past its smoke point, it can cause food to stick to the pan. This is because the oil has broken down and is no longer acting as an effective lubricant between the pan and the food. The food then comes into direct contact with the pan, and a chemical bond can form between the two.

To prevent food from sticking, it is important to heat the pan first and then add oil, ensuring that it does not exceed its smoke point. This will create a layer of lubrication between the pan and the food, preventing the formation of chemical bonds.

High heat causes proteins and carbs to bond with the pan

High heat causes proteins and carbohydrates to bond with the pan. This is due to the chemical reaction between the food and the pan's surface. When a pan is heated, the metal expands, and food can get trapped in microscopic cracks, causing it to stick and burn. Proteins and carbohydrates are particularly prone to this.

Proteins are long molecules that start to break apart and lose moisture when exposed to heat. This process, known as coagulation, begins at 140°F. High-protein foods shrink when cooked because of this. Additionally, high heat can cause a process called browning, which is caused by a Maillard reaction, where enzymes in the food are destroyed.

Carbohydrates, on the other hand, absorb moisture from their surroundings and become softer when heated. This process is called gelatinization and begins at 150°F. It is why pasta and rice double in size and soften when cooked.

When cooking with oil, it is essential to maintain the right temperature to prevent the oil from forming a stable polymer that bonds with the pan's surface. This is achieved by ensuring that food is in contact with the pan, as it will help keep the temperature down and reduce the chance of the oil bonding with the pan.

To prevent food from sticking to the pan, it is recommended to season the pan, ensure it is hot before adding food, and dry the food before placing it in the pan.

Non-stick pans can lose their coating over time

Non-stick pans are great, but they can lose their non-stick coating over time. This can happen within a year, or two to three years, and is generally inevitable within three to five years. The non-stick coating will break down, and food will begin to stick to the pan. This is because, over time, oils can bake into the pan, building up with each use and affecting the pan's protective barrier. Grease and food particles can build up in scratches and crevices in the pan, and this buildup can affect the balance of the non-stick layer, causing chemical reactions that change the molecular design of the protective coating.

However, there are ways to restore a non-stick pan. One method is to create a mixture of vinegar and water, which can react with and help dissolve stuck-on particles. Bring this mixture to a boil in the pan, then simmer for ten minutes, allowing the vinegar to bond with oil residue. After this, the pan can be wiped clean, and the inside can be scrubbed with baking soda, which can absorb and remove stuck substances. The pan can then be rinsed and washed as normal.

Using metal utensils on non-stick pans can cause sticking

Non-stick pans are coated with Teflon, a non-toxic chemical that creates a frictionless surface. This makes cooking easier as it prevents food from sticking to the pan. However, using metal utensils on non-stick pans can cause these pans to lose their non-stick capabilities over time.

Metal utensils, such as spatulas and spoons, have sharp edges that can chip away and scratch the Teflon coating of the pan. This not only damages the non-stick surface but also results in tiny pieces of the coating chipping off into your food. Therefore, it is recommended to use wooden, plastic, or silicone utensils with non-stick pans. These alternatives are safer to use as they will not scratch or damage the coating.

It is important to note that the "don't use metal" rule applies not only to cooking utensils but also to cleaning tools. Using abrasive materials like steel wool to scrub your non-stick pans can also scratch and damage the coating.

By avoiding the use of metal utensils and abrasive cleaning tools, you can help maintain the integrity of your non-stick pans and ensure their longevity in the kitchen.

Cast iron pans need to be seasoned

Cast iron pans are a great investment for your kitchen, but they do need a little extra care to keep them in top condition. Seasoning your cast iron pan will create a hard, protective coating that will make it practically non-stick. This coating is formed by heating thin layers of fat (like oil) on the cast iron, which then bond to the metal and to each other in a process called polymerization.

How to Season Your Cast Iron Pan:

Step 1: Wash and Dry Your Pan

Give your pan a good scrub with warm, soapy water, then dry it thoroughly. You can use a stovetop flame for a minute or two to ensure all the water is gone.

Step 2: Oil Your Pan

Using a paper towel, coat the pan with a thin film of neutral oil like canola, vegetable, grapeseed, or sunflower oil. Be sure to cover the bottom and handle of the pan. Wipe away any excess oil so that the pan feels dry to the touch.

Step 3: Bake the Pan

Place the pan upside down in the oven and bake at a temperature between 350-450°F for about an hour. This will allow the oil to polymerize and form a hard coating. Using the oven ensures an even heat for more effective seasoning.

Step 4: Cool the Pan

Turn off the oven and let the pan cool down inside before touching it.

Step 5: Repeat

Repeat these steps multiple times to build up a smooth finish. A well-seasoned cast iron pan will have a black patina that is slick enough for eggs to skate across, but tough enough to withstand the heat needed to sear a steak.

Frequently asked questions