Tagged: oxidation
A Camera Can Now Grade How Fermented Your Tieguanyin Is
A 2026 study taught machine-learning models to read Tieguanyin's fermentation stage from ordinary photos and hyperspectral scans, graded against a two-of-three vote among tea masters, not a chemical threshold and not one expert's word alone.
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.
Oolong Carried the Least of a Compound Class in a Five-Tea Study
A 2026 study measured advanced glycation end-products, compounds tied to inflammation, across five tea types. Oolong came out lowest of all five.
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.
Light and Roasted Oolong Bring Different Chemistry to the Kettle
Brewing temperature moved caffeine significantly only in oolong in one 2025 study, and roasted and unroasted oolong draw on different aroma chemistry.
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.
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.
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 and the roast each contribute, and why the received account of the locked glycoside pool is contradicted by direct measurement.
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 later defect that only resembles one.
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.
Oolong Polyphenols
The compound family behind color and astringency. What catechins, theaflavins, and thearubigins actually are, structurally, and what partial oxidation does to each before the leaf ever reaches a cup.
Storage and Aging
Most oolong is made to drink young. A roasted minority is made, and stored, to be re-roasted and drunk decades later. What changes in the leaf, and how it differs from aging pu-erh.
Oolong Tea
Oolong is partly oxidized Camellia sinensis, made to a chosen point between green and black: how it is made, the major style families, how it tastes across the spectrum, and why it is brewed gongfu.