Kitchen Chemistry

The dangers of the kitchen

Oil is an essential cooking ingredient. We use it to pour over salads and even fry with it. Oil, though, is a special chemical that, unlike water, can heat up to temperatures way above 100^oC. This makes oil one of the most dangerous chemicals in the kitchen. But why do we use oil?

Well two great reasons:
- the fact that oil can reach higher temperatures than water means food cooks faster
- because oil does not mix with water, food is cooked to a tasty crisp on the outside while soft and delicate on the inside. Think of your fish-and-chips.

When you put chips or fish into the deep fryer you quickly see bubbles rising from the food. Drying out of the surface of the food is taking place as the water is quickly vapourised and removed as a gas from the hot oil. Now the food will be crisp on the outside and soft on the inside.

Water is not always the ideal substance to put out fire. It depends on what is burning. If its oil that is burning then watch out, water is a big no no. So what makes oil so dangerous? Well the exact same reasons given above.

Consider the video on the right. It was from a Government advertising program against putting out oil fires with water. It really reminds you to never heat oil unless an adult is present with you.

Now canola oil can be heated to temperatures above 230 ^oC. Water, on the other hand, instantly turns to vapour at 100^oC. So when water is poured onto the hot, burning oil it sinks to the bottom and instantly turns to gas erupting out of the oil and taking the burning oil with it.

Sourcedfromhttps://www.youtube.com/watch?v=rQ6ZWQztmpY
8/06/20 10.55 am.

Consider the video on the right. It shows some of the properties of oil that makes it very dangerous if not handled properly.

1) What is flash point?

2) What is flame point?

3) What is auto ignition?

4) Why must you never remove the lid from a smoking pan of hot oil?

sourced from https://www.youtube.com/watch?v=suce6QNkVRI 27/06/20 12.07