07/20/2026
Glass is one of the worst things you can store tea in, and here’s why: UV light passes straight through it, and the curve of the glass actually acts like a magnifying lens, concentrating both UV and heat directly onto the leaves. The same way a magnifying glass can start a fire in sunlight, a glass jar is slowly accelerating the degradation of your tea every time light hits it.
For matcha specifically, you’ll notice the colour fading first, that vibrant green turning dull and yellowish.