Why is there a small glass ball in Japanese soda bottles?!
Best Answer - Chosen by Voters
In the Meiji Era(1868-), the sailors in the Japanese Navy had drank the soda usually for rehydration on the hot sea.
They needed a cap of a bottle that was usable many times and could shut easily by overturning.
So the small glass ball was adopted as a cap.
By the way, the soda is called "Lamune"(come from Lemonade).
That Ball is stored in the lid before you open it, then once the top is twisted (to open it) it falls into the drink to create the bubbles.
ancient chinese secret. I will never tell you.