The Great Banana Race: A Kitchen Test Graph

Kitchen Science with Priya and Grandpa: The Great Banana Race

1Grandpa likes his bananas sweet and soft, but the bananas at the store are often green and hard. Bananas are usually picked before they are ripe, and they keep ripening after they are picked. As a banana ripens, much of its starch turns into sugar. The fruit gets softer, sweeter and more yellow. Grandpa and I wanted to know where in our home a green banana would ripen fastest.

2We took four green bananas from the same bunch and gave each one a different spot. We put the first banana alone in a paper bag. The second banana went into a paper bag with a ripe apple. The third banana sat in the fruit bowl on the kitchen counter. The fourth banana went into a cardboard box in our cool basement.

3Every morning, we checked all four bananas. We called a banana ripe when its peel was all yellow with a few brown freckles. We wrote down how many days each banana took to get there, and I made a bar graph of our results.

4Here is why the spots made a difference. Ripening fruit gives off a natural gas called ethylene. This gas tells the fruit to ripen faster. A paper bag holds the gas close to the banana instead of letting it drift away. Apples give off ethylene too, so an apple in the bag adds even more of the gas. Temperature matters as well. Warmth speeds up ripening, and cool air slows it down.

5Our test showed that where you keep a banana can change when you get to eat it. Next time, Grandpa wants to test pears.