Small notes on brewing tea at home.
Most green teas turn bitter when brewed with boiling water. Let the kettle rest for two or three minutes, or aim for 75–80 °C. Oolongs like it hotter, around 90 °C, and black teas are happy with water straight off the boil.
Instead of one long steep, try several short ones of 20–30 seconds each. You will notice how the flavour shifts from cup to cup: grassy, then sweet, then mineral.
Keep tea away from light, heat, moisture and strong smells. An opaque tin in a kitchen cupboard far from the stove is enough for most teas.