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 The Order of the Seventh Steep
The Order of the Seventh Steep
OOLONG
Semper Partim Oxidatum Always partly oxidized

Tagged: oxidation

Article · science

Oolong Stays Floral Even Fermented Into Kombucha

A 2026 five-tea kombucha study found oolong's floral, fruity character came through the ferment strongest of the five, while black and pu-erh's own character mostly gave way to the culture's earthier profile. Oolong also tied green tea for the most antioxidant of the five.

Jul 27, 2026
Article · Health & Science

Oolong Carried the Least of a Compound Class That Should Have Favored Green Tea

A 2026 study measured advanced glycation end-products, the same compounds tied to aging and inflammation, across five tea types. Oolong came out lowest of all five, and the antioxidant story that usually explains oolong's health claims does not explain why.

Jul 19, 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
Article · Health & Science

Why a Green Oolong and a Heavy Roast Never Want the Same Water

The brewing guide states the temperature bands by oxidation level. Here is the extraction chemistry, measured in real studies, that makes them true.

Jun 4, 2026
Article · science

Two Reactions Start When the Leaf Is Bruised, Not One

Shaking bruises the leaf once, but it starts two separate reactions on two different substrates. One reddens the edge. The other, mapped only in the last few years, manufactures the floral scent.

Apr 24, 2026
Article · science

Same Leaf, Split Into Green and Black, Kept Almost the Same Caffeine

Catechins collapsed by more than ninety percent between the two halves. Caffeine barely moved. Oxidation, the reaction that defines oolong, is not what decides how much of it ends up in the leaf.

Feb 23, 2026
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.

Guide · Health & Science

Oolong Polyphenols

The compound family behind color, astringency, and every published health claim. What catechins, theaflavins, and thearubigins actually are, structurally, and what partial oxidation does to each before the leaf ever reaches a cup.

Guide · Oxidation & Roast

Storage and Aging

Most oolong is made to drink young and does not improve in a drawer. A roasted minority is made, and stored, to be re-roasted every few years and drunk decades later. The Standard on how that works, what changes in the leaf, and how it differs from aging pu-erh.

Guide · Basics

What Is Oolong Tea

Oolong is partly oxidized Camellia sinensis, made to a chosen point between green and black. This is the canonical account of what it is, how it is made, the major style families, how it tastes across the spectrum, and why it is brewed gongfu.