Why (and how) do foods stick to a pan?

  • Thread starter Ganesh Ujwal
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In summary, foods high in protein tend to stick to pans and other metal surfaces due to a lack of easy-rendering fat. To counteract this, oil or butter is often added to the pan before cooking. The dominant factors in the physics of sticking include the material's density, chemical composition, elasticity, and specific heat, as well as the state of the surface such as temperature and roughness. The phenomena responsible for sticking can include lubrication, intermolecular forces, and order-disorder phase transitions. Overall, the stickiness of food is influenced by the presence of scratches on the pan and the transition of the food from a fluid to a more solid stage during cooking.
  • #1
We all (sooner or later) have noticed that foods relatively high in protein (especially those low in fat) are very prone to sticking to a pan, or in general to any non-specially-coated metal surface. For example really lean white fish, which is almost all protein, is one of those devils which will always want to stick. Likewise, egg whites can stick. To some extent, almost any food that doesn't have a generous amount of easy-rendering fat seems to stick, but higher protein is more sticky.

To counteract this tendency, one learns to compensate by putting some kind of fat (usually oil or butter) into the pan in advance of the food. Most people seem to get the best result by preheating the dry pan some, then adding the oil, letting it get up to temperature, then adding the food.

I was just trying to ask myself what would be a simple and general sketch of what is going on on the surface of a pan when sticking takes place, and in particular:

1) what features of a material (density, chemical composition, elasticity, specific heat,etc.)

2) and of the state of the surface (temperature, roughness, etc.)

have a dominant role in the physics of such a system.

3) Which phenomena (lubrication, intermolecular forces, order-disorder phase-transitions, etc.) are more likely to be responsible for what we experience in our every-day life.
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  • #2
Food sticks when cooking when there are scratches in the pan and the food has a fluid(ish) stage followed by a more solid stage (burned food sticks).
What makes something sticky is actually quite complicated, and with food, the situation is changing due to the heating.

1. Why do foods stick to a pan?

Foods stick to a pan due to a process called "adhesion." When food is heated and placed on a pan, the heat causes the food's molecules to become more active and move around. These molecules then attach to the molecules of the pan, creating a strong bond that causes the food to stick.

2. How does the type of pan affect food sticking?

The type of pan used can greatly affect how food sticks. Non-stick pans have a special coating that prevents food from adhering to the surface. Cast iron and stainless steel pans may require seasoning or preheating to create a non-stick surface. Additionally, the type of oil or cooking spray used can also play a role in preventing food from sticking.

3. Can cooking at high temperatures prevent food from sticking?

Cooking at high temperatures can actually make food stick more. As the pan heats up, the molecules of the metal expand and create a rougher surface, making it easier for food to stick. It is important to use the appropriate cooking temperature for the type of food being cooked to prevent sticking.

4. How can I prevent food from sticking to a pan?

There are a few techniques that can help prevent food from sticking to a pan. One method is to preheat the pan before adding the food, as this creates a barrier between the food and the pan's surface. Using a non-stick pan or adding a small amount of oil or cooking spray can also help prevent sticking. Additionally, using a spatula or tongs to move the food around in the pan can help prevent it from forming a strong bond with the surface.

5. Why do foods stick more to stainless steel pans compared to non-stick pans?

Stainless steel pans do not have a non-stick coating, so there is nothing preventing the food from sticking to the surface. Additionally, stainless steel is a poor conductor of heat, so food may stick more if the pan is not preheated properly. Non-stick pans have a special coating that creates a barrier between the food and the surface, making it more difficult for the food to stick.

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