Salt and pepper are seasonings that I sometimes use when I am cooking to make some types of foods taste better. I keep them in special plastic pots with twisty tops that grind the salt or pepper into a fine powder that can be used easily to flavour our food. But my daughters want to know why the salt pot has a lid, when the pepper pot does not?
The salt we use in cooking is a chemical compound called sodium chloride. It is a mineral made of sodium (chemical symbol: Na) and chlorine (chemical symbol: Cl), and is found in sea water. We can get it out of the sea by boiling or evaporating off the water, leaving behind the white salt crystals.
Salt is important for preserving foods to stop them from going bad or rotten, and it can also make foods taste different or better, which is why people sometimes use it when they are cooking, storing or eating foods. Salty is one the five basic tastes our tongues can sense – the others are: sour, sweet, bitter and savoury (also called ‘umami’).
Salt used to be a very valuable substance – in olden times, some people used to swap it for other products instead of using money! Salt also has an important job to do inside your body for some of the chemical reactions that keep you alive but eating too much of it can make you sick.
Salt dissolves easily in water and it will soak up moisture (tiny water droplets) from the air. If you don’t keep it really dry, it will clump up in to big, hard lumps of salt crystal. So, that’s why I put a lid on my salt pot – to keep the moisture out and my salt nice and dry!
But what about pepper?
Pepper comes from a plant that grows in India. The fruits of this type of plant can be dried and crushed up for use in cooking. We call these dried fruits ‘peppercorns’ and when we put them in food, they taste a bit hot and spicy. Pepper is the most widely bought and sold spice in the world – it is used to make food taste good and to make some kinds of medicines!
Pepper doesn’t dissolve in water like salt does. It doesn’t get spoiled by moisture in the air, like salt does, but it can lose some of its peppery flavour if it is kept it in bright light or open air for a long time. So, I keep my pepper in its twisty-top pot in a dark cupboard.