これさえ読めば安心! How to Get Tea Stains Outの活用法をロジカルに解説します。

First, a quick science moment—don’t worry, I’ll keep it painless. Tea contains tannins, which are basically nature’s way of making your cup look like a crime scene. Tannins bond to porous surfaces (like ceramic and enamel) faster than you can say “biscuit.” The longer you leave that stain, the more it throws a house party and invites its friends: rust from hard water and leftover oils. Lucky for us, baking soda is the bouncer that kicks them out.