Glossary · Chemistry
Total phenolics
Definition
The aggregate measure of phenolic material in a juice or cider, usually determined by a colorimetric method and expressed as an equivalent of a reference compound. It is what most historic "tannin" figures actually record.
- Subject
- Chemistry
In more detail
Because the assay responds to any oxidisable phenol, it counts chlorogenic acid, phloridzin and other non-tannin phenolics along with procyanidins. It is a useful comparative number and a poor structural one, and figures from different methods and eras should not be pooled.
Where this is covered properly
The glossary defines; these pages explain. Each is described in its own words.
Related terms
Terms that belong to the same part of the subject, or that this one is routinely confused with.
Chemistry
Tannin
In cider usage, the phenolic material responsible for bitterness and astringency, principally condensed tannins — procyanidins — built from catechin and epicatechin units.
Chemistry
Polyphenol
The broad class of plant compounds carrying multiple phenol rings. In apples this includes procyanidins, hydroxycinnamic acids such as chlorogenic acid, flavonols, dihydrochalcones such as phloridzin, and anthocyanins in red-fleshed fruit.
Chemistry
Procyanidin
A chain of flavan-3-ol units — mainly epicatechin, with catechin as a terminal unit — and the principal tannin of cider apples. Chain length determines whether it tastes bitter or astringent.
History
Long Ashton Research Station
The Somerset research station, founded as the National Fruit and Cider Institute in 1903 and later part of the University of Bristol, whose analyses of cider fruit and fermentation underpin most English cider science.
Where to go next
- Cider glossary — The whole vocabulary, by subject and A–Z.
- Comparisons — Terms that are only really clear when set against the thing they are not.
- Search — Finds terms by their aliases and by their spellings in other languages.
Sources
What this page rests on. Where a source is marked as registered rather than read, CiderHQ is recording that the body is authoritative on the subject without claiming to have worked through the document itself. See our evidence policy for what each state means.
Long Ashton Research Station cider fruit analyses
National Fruit and Cider Institute / University of Bristol · research institute · registered as competent for this subject · covers 1903–2003
The foundational body of cider-fruit science in English. Long Ashton produced the acid-and-tannin classification that divides cider apples into sweet, sharp, bittersweet and bittersharp, and analysed hundreds of cultivars grown at its Somerset site. Its figures are historic measurements of specific fruit at a specific place, not universal constants — a distinction CiderHQ preserves in every measurement record that cites it.
Peer-reviewed literature on apple phenolics and cider sensory perception
Various journals · peer-reviewed literature · registered as competent for this subject
Registered as a class rather than as one paper, because the mechanisms CiderHQ describes — tannin chain length driving the split between bitterness and astringency, salivary protein precipitation, enzymatic browning — are established across many studies rather than resting on any single one. Individual papers are cited where a specific number is quoted.