Do I need a fairness cup (tea pitcher)?
Most gongfu sets include a glass pitcher — is it just for show?
Functional, not decoration. The fairness cup (cha hai, 茶海) is where you pour the entire steeped batch from the gaiwan/pot before serving. Two reasons: (1) it stops the steep instantly — leaves don't keep extracting; (2) it homogenizes the brew so the first cup poured and the last cup poured taste identical (the 'fairness' part). Without it, the first cup is weak and the last is bitter. €8 of glass is worth every cent — by far the highest-impact upgrade for any gongfu beginner.
— Yurii — 931 Tea, 931 Tea