🫘 Do soaked beans sprout faster?

My hypothesis

If I change how long the beans are soaked first, then how many of the five beans have sprouted by day four will ______, because ______.

🔊 You fill in the blanks. Think about what a dry bean has to take in before it can wake up. A guess is a good because: the test finds out.

Change, measure, keep the same

Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.

What you need

• 🫘 Dried beans from the grocery bag (pinto, lima or kidney): 45, all the same kind
• 🥛 Clear plastic cups, all the same size: 2, for soaking
• 🛍️ Plastic bags: 9 zip bags
• 🧻 Paper towels
• 🚰 Water from the tap
• ⏱️ A stopwatch or a kitchen timer
• 🩹 Masking tape, to mark lines
• 🖍️ Crayons or markers

Steps

1. The evening before, put 15 beans in a cup of water to soak overnight.🔊
2. Next day, put 15 more beans in a second cup of water, and set a timer for four hours.🔊
3. While you wait, fold a damp towel into nine zip bags and label three each: dry, 4 hours, overnight.🔊
4. When the timer rings, put five beans of the right kind on the towel in each bag.🔊
5. Zip each bag almost shut, and tape all nine to a wall in one warm room, out of direct sun.🔊
6. Every day, add a few drops of water to any dry towel, and tell a grown-up if a bag smells bad.🔊
7. Every day, count the beans in each bag with a little white root poking out.🔊
8. On day four, write each bag's count in your table.🔊
9. Keep counting until day seven, to see if the slow beans catch up.🔊
10. Draw a bar graph of beans sprouted for each soaking time.🔊
11. Wash your hands after touching the beans, and never eat them.🔊

Every step is one you can do yourself, with a grown-up nearby. Write each number down straight away, in the table below, so nothing is lost.

Your results table

From 4th grade, add the tries for each level and divide by how many there were: that's the mean, and it goes in the last column. Then draw a bar graph, one bar for each thing you tried.

Why it works

🔊 A dry bean is a sleeping plant with its food packed beside it, and it can't wake up until water gets inside. Soaking lets the bean swell and soften, so the root can push out sooner. Beans that soak longer often sprout first, though every bean wakes up at its own speed.

Going further (7th and up): Change a second thing: soak the beans for 2, 8 and 24 hours, and draw a line of how many have sprouted each day.

Board layout

This project at your grade

From 4th grade up, the table gets a mean column. See every project for 2nd grade, or print a blank results table.

What a judge will ask

• What did you change, and what did you measure? I changed how long the beans are soaked first and measured how many of the five beans have sprouted by day four, in beans sprouted, of 5.
• What did you keep the same, and why does that matter? I kept the same kind of bean and five beans and a damp towel in every bag the same, so the only difference was how long the beans are soaked first.
• How many times did you test it? 3 times at each of my 3 levels.
• If you did it again, what would you change or test next? I'd soak the beans for 2, 8 and 24 hours, and draw a line of how many have sprouted each day.

Make it yours

Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.

Try next

• 🌡️ Do seeds sprout faster somewhere warm?3rd–7th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
• 🫘 How much water do bean seeds need to sprout?2nd–6th grade · 10 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants