Ocean in a Bottle

A calm-down jar and a science demo in one: tip the bottle and a tiny blue wave rolls back and forth. This is the craft at the end of The Great Lemonade Strike.

10 minutes · Ages 6-9 with a grown-up · Mess: Low (one oil spill risk)

What you need

• □A clear plastic bottle with a tight lid (a 16–20 oz water bottle is perfect)
• □Water — enough to fill the bottle about halfway
• □Baby oil or vegetable oil — enough to fill the rest
• □Blue food coloring (2–3 drops)
• □Optional: glitter, tiny shells, a small plastic fish or boat
• □Strong tape or hot glue for sealing the lid

How to make it

1. 1. Fill it halfway with water

   Pour water into the bottle until it's about half full. Leave the rest for oil.

2. 2. Add the blue

   Two or three drops of blue food coloring. Cap it and tip once to mix the water only.

3. 3. Fill the rest with oil

   Slowly pour oil on top until the bottle is almost full. The oil sits on the water — that's the science.

4. 4. Optional sparkle

   A pinch of glitter or a tiny toy boat. Less is more or you will have a glitter blizzard.

5. 5. Seal the lid

   A grown-up should tape or hot-glue the lid so it cannot open in a backpack.

6. 6. Tip it

   Slowly tip the bottle on its side. A tiny blue wave rolls back and forth. That is your ocean.

From The Great Lemonade Strike by PJ King.