The science behind cooking

COOKING is a science.

Food preparation and cookery involve many physical and chemical reactions that take place during the process.

Try these two experiments in the kitchen.

Find out why some kinds of fruit work in jelly and others don’t. You will need:

I packet of jelly crystals Chopped fruit – apple, orange, kiwi, banana, fresh and tinned pineapple

What to do:

1. Mix up the jelly according to the instructions on the box.

2. Place each of the chopped fruit in a separate container.

3. Add some jelly to each container of fruit and have a further container with just jelly as a control.

4. Put the containers in the fridge to set.

What happens?

Does all the jelly set properly?

Which fruits work well? Which fruits contain an enzyme that doesn’t allow the gelatin in jelly to work?

What difference is there between fresh pineapple and tinned pineapple?

Have you ever wondered what makes the dough and

batter of breads and cakes rise? You will need:

1 packet of yeast

1 cup very warm water 2 tablespoons sugar A large balloon

A small (1 litre) empty plastic bottle

What to do:

1. Stretch out the balloon by blowing it up repeatedly and then lay it aside.

2. Add the packet of yeast and the sugar to the cup of warm water and stir.

3. Once the yeast and sugar have dissolved, pour the mixture into the bottle.

4. Attach the balloon to the mouth of the bottle.

5. Observe what happens.

What’s going on?

As the yeast feeds on the sugar it produces carbon dioxide. This gas fills the balloon. A very similar process happens to make bread rise.