Est. 1956 · The Order The independent guide to oolong: the partly oxidized teas, and how to brew them Oolong.biz
THE ORDER OF THE SEVENTH STEEP SEMPER PARTIM OXIDATUM OOLONGThe Order of the Seventh Steep
The Order of the Seventh Steep
OOLONG
Semper Partim Oxidatum Always partly oxidized

Tagged: processing

Article · Oxidation & Roast

The Stem Concentrates Floral Compounds the Leaf Does Not

A 2025 tissue-level study found oolong's stem holds more of the compounds behind its floral scent than the leaf beside it. A 2022 study found adding stem to the blend lowers one of those same compounds in the finished tea. Neither team was answering the other's question, and nobody has reconciled the two.

Aug 2, 2026
Article · Basics

Why one plant makes green, oolong, and black tea

Green, oolong, and black tea are the same leaf from Camellia sinensis. What separates them is processing, above all how much enzymatic oxidation the maker allows before heat arrests it.

Jul 1, 2026
Guide · Oxidation & Roast

Oolong Aroma

More than 300 volatiles have been identified in oolong, and most of them were not in the fresh leaf. What the stress route, the locked glycoside pool, and the roast each contribute, and why the received account of the second one is contradicted by direct measurement.

Guide · Oxidation & Roast

Kill-Green

The heat step that arrests enzymatic oxidation in oolong. What denatures the enzymes and why it cannot be undone, the wok and the drum with their real numbers, how a maker judges it done, the two ways it fails, and the storage defect that only resembles one.

Guide · Oxidation & Roast

Oolong Oxidation and Roast

The two axes that define an oolong. What enzymatic oxidation is and how it is arrested by kill-green, why oolong sits partly oxidized between green and black, and how roasting is a separate step applied afterward.