Blog

What's Inside a Tenmoku Cup? XRF Mineral Analysis Reveals the Full Composition X-ray fluorescence (XRF) analysis of ten tenmoku cups shows a consistent mineral profile: 62–68% SiO₂, 12–16% Al₂O₃, 5–8% Fe₂O₃, 3–5% K₂O, a...

Why Oil Spot Patterns Form: The Crystallography Behind Tenmoku's Most Prized Surface Oil spot patterns on tenmoku are crystallized iron oxide — specifically, the rare ε-Fe₂O₃ phase that only forms under precise temperat...

Does Iron-Rich Tenmoku Glaze Change Your Tea's pH? We Measured It Yes — tenmoku raises your tea's pH by 0.3 to 0.5 points, shifting it toward less acidic. When you brew the same tea in a tenmoku cup versus a glass contr...

Is Tenmoku Food-Safe? What Leachability Testing Actually Shows Yes — properly fired tenmoku passes standard food-safety leachability tests. Multiple independent laboratory analyzes of Song Dynasty-style Jian Zhan cups h...

What Happens Inside a Tenmoku Kiln at 1,300°C: The Chemistry That Creates Those Patterns At exactly 1,300°C (2,370°F), iron oxide in tenmoku glaze undergoes a phase transformation that no lower temperature can achieve. ...

Iron-rich tenmoku tea cups release approximately 0.1-0.3 mg of iron ions per liter of brewed tea — a measurable amount that interacts with tea polyphenols to reduce astringency and enhance perceived sweetness. The scienc...

How Durable Is a Handmade Tenmoku Cup? We Drop-Tested 5 to Find Out We dropped five handmade tenmoku cups from table height onto hardwood. Three survived intact. Two chipped but did not shatter. Zero shattered into piec...

Yes, Tenmoku Handles Boiling Water — We Tested 10 Cups to Prove It We poured 212°F water into ten tenmoku cups straight off the boil. None cracked. At Zen Tea Cup, we wanted definitive data on thermal shock resistance, ...

Yes, Tenmoku Thick Walls Keep Your Tea at the Perfect Sipping Temperature We measured this with real thermometers. If you pour 200°F water into a tenmoku cup and a thin porcelain cup, the tenmoku keeps your drink in the...

Yes, Tenmoku Changes the Taste of Plain Water — Here Is the Proof We tested this ourselves. If you pour the same filtered water into a tenmoku bowl and a glass cup, you will taste a measurable difference. At Zen Tea Cup...