Radish juice is red, right?

radish on wooden cutting board with knife

In the laboratory, chemists use ready-made test sticks ‏(pH indicators) that can change color to determine whether a liquid is acidic. Unfortunately, we don’t have anything like that at home. But we can make our own “test tool”: with radish juice. How does radish juice change color when it comes into contact with liquids with different acidities?

Before you get started

If you are experimenting at home:
1. Let your parents know and discuss the experiments with them beforehand.
2. Do not eat or drink at your workspace.
3. Wash your hands thoroughly before and after the experiment.
4. Be careful and cautious with the materials.

Graphic figure boy pouring liquid in flask

You will need

Approximately 140 g radishes
Kettle
Glass bowl
Sieve
Scales
Measuring cup
Cutting board and knife
Empty jam jars
Tap water
“Test liquids”: dishwashing liquid, citric acid solution, aqueous solution of baking soda

Let’s get started!

radish cut in small pieces on wooden cutting board

1. Weigh radishes and cut into small pieces

Weigh 140 g of radishes and carefully chop them with a kitchen knife.

2. Infuse in water

Pour as much hot water from the faucet as possible over the radishes and let everything steep for about 15 minutes.

radish juice is poured through sieve into a glass

3. Filter

Pour the radish juice through a sieve into a glass jar ‏(e.g., empty jam jar).

row of five glas jars with clear liquids

4. Prepare tests

Now you can choose the liquids you want to examine with the radish juice. You need a separate jar for each liquid that you want to examine. Place a piece of paper in front of each jar and number the pieces of paper from 1 to 5.
For example, you can test:
50 ml tap water + 50 ml citric acid.
90 ml tap water + 10 ml dishwashing liquid
100 ml distilled water
100 ml tap water
100 ml tap water + 1 teaspoon baking soda