In the cup
Green tea territory
- Liquor
- Bright green
- Body
- Light
- Finish
- Fresh
Grassy, vegetal, fresh spring sweetness.
Oxidation & Roast
Two transformations shape what ends up in the cup. Move the sliders to see how oxidation and roast affect color, body, aroma, and finish.
Oxidation
Leaf chemistry
When leaf cells are bruised during withering or rolling, enzymes oxidize catechins into darker, fruitier, brisker compounds. Heating the leaf — fixation, or kill-green (杀青) — stops most enzymatic oxidation. Roast, if any, comes after.
Roast
Applied heat
Roasting uses dry heat after oxidation has been halted. It can soften green notes, reduce sharpness, deepen sweetness, and add toasted grain, nuts, caramel, cocoa, charcoal, or baked-fruit aromas. Heavy roast can mute florals and make the finish drier.
Examples
Try a tea style
Percentages here are illustrative, not measured. Tea makers usually describe oxidation and roast comparatively rather than by exact numbers, and cultivar, season, leaf grade, storage, and brewing all change the cup.
How to read this map
Oxidation changes the leaf.
Oxidation is a chemical process. Once the leaf surface is disturbed, oxygen transforms aroma, color, and structure. Green teas are heated early to preserve freshness. Oolongs sit in the middle. Black teas are allowed to oxidize much further.
Roast changes the finish.
Roast is a heat process layered onto the tea. A light roast can soften green edges. A deeper roast can bring nuts, caramel, dried fruit, or charcoal. This is why a lightly oxidized tea can still taste deeply toasted.
The two axes are independent.
A tea can be low oxidation and high roast, like hojicha (a roasted green tea). It can be high oxidation and low roast, like most black teas. Post-fermented teas like pu-erh add another process and sit outside this map.
The map is a useful simplification.
A white tea and a light oolong can land on the same square here and taste completely different. Oolong adds two steps the map doesn't show — bruising the leaf to start oxidation in a controlled way, then firing it to halt the enzymes. White tea skips both, so its enzymes stay alive and it keeps evolving in the bag. Heavily roasted white tea isn't really a category for the same reason — without firing first, you'd push the leaf into something else.