Science
The datasets behind the numbers
Every measured figure on this site came from one of eleven programmes. These are the programmes: what each measured, where, when, by what method, and which of them may be read in one column with which.
CiderHQ holds 1,746 transcribed measurements across 326 cultivar records. None of them is averaged with any other, and this page exists to explain why that is a decision rather than an omission.
Described in full
- Shape
- Four stacked panels, one per programme, each naming the place, the period and the substrate that was analysed. Within each panel the figures that programme published for Kingston Black are listed with their units. The fourth panel is set apart by a dashed border and a heading that reads "finished cider, not juice".
- WSU Mount Vernon, Skagit Valley, Washington, 2002–2017, juice
- pH 3.51, total acid 0.61% w/v, total tannin 0.15% w/v, specific gravity 1.055, 13.3 °Bx. A maritime North American site chosen as the closest analogue to the English West Country, averaged across the seasons the cultivar was in trial.
- USDA-PGRU Geneva, New York, 2017, juice
- pH 4.23, titratable acidity 2.1 g/L, total phenolics 1,080 mg/L, 12.5 °Bx. One season, one harvest, in a continental climate with hotter summers and colder winters than the Skagit Valley. The pH is 0.72 units above the Mount Vernon figure for the same cultivar.
- Long Ashton, Somerset, 1905–1975, juice
- Total acid 0.58% w/v, total tannin 0.20% w/v. A seventy-year composite from the station whose figures underlie the English classification. Its tannin figure is a third higher than Mount Vernon’s for the same fruit.
- Geneva, New York, late 1970s, finished cider
- Finished pH 3.56, finished total acid 0.58% w/v, finished total tannin 0.062% w/v. Set apart because it is a different quantity with the same name: fermentation, fining and time remove phenolic material, so this tannin figure is roughly a third of the Long Ashton juice figure and cannot be read as disagreeing with it.
- What the figure argues
- The pH spread across the three juice analyses is 3.51 to 4.23, which is large enough to change what a maker would do about it, and none of the three is an error. A measurement is a statement about a fruit and a place and a season and a method. Averaging the four would produce a number that no orchard ever grew and no laboratory ever measured.
Why the same fruit has four different numbers
Kingston Black is the most analysed cider apple in the English-speaking world, and four of the programmes below measured it. Its juice pH comes out at 3.51 in the Skagit Valley and 4.23 in the Finger Lakes — a difference large enough to change what a maker would do about it. Neither figure is wrong. They are measurements of different trees, in different climates, in different years.
The fourth figure is subtler and more dangerous. Geneva’s 3.56 looks like a tiebreaker between the other two, and it is not a juice measurement at all: it was taken on finished cider, after a fermentation had consumed acid and a fining had stripped phenolics. Put in one column with the others it would look like corroboration. It is a different quantity with the same name.
That is the failure these pages exist to prevent. A figure without its programme is not a fact about a fruit; it is a fact about an orchard, a season, a laboratory and an assay, and CiderHQ publishes all four.
The eleven programmes
Ordered by how much of the site rests on them.
| Dataset | Where | When | Cultivars | Measurements |
|---|---|---|---|---|
| The DOP Sidra de Asturias varietal characterisation | Asturias | Published characterisation, retrieved 2026-08-24 | 56 | 114 |
| The Long Ashton cider apple table | Long Ashton Research Station | 1905–1975 | 43 | 86 |
| The Three Counties perry pear survey | Gloucestershire | 2022–2024 | 38 | 308 |
| The USDA-PGRU germplasm characterisation | USDA-ARS Plant Genetic Resources Unit | 2017 | 47 | 560 |
| The WSU Mount Vernon cider cultivar trial | Northwestern Washington Research and Extension Center | 2002–2017 | 46 | 311 |
| The Geneva finished-cider analyses | New York State Agricultural Experiment Station | late 1970s | 17 | 63 |
| The IFPC cider apple juice characterisation | France — orchards supplying the Institut Français des Productions Cidricoles | 2018 | 12 | 48 |
| The Klosterneuburg Mostbirnen trial | Versuchsgut Haschhof | 2007–2008 | 13 | 64 |
| The Long Ashton perry pear analyses | Long Ashton Research Station | 1903–1963 | 19 | 57 |
| The Virginia polyphenol characterisation | Winchester | 2012–2013 | 17 | 68 |
| Typical English apple juice analyses | England — the compilation does not name the orchards | 1922–1977 | 18 | 67 |
Published characterisation, retrieved 2026-08-24
The DOP Sidra de Asturias varietal characterisation
The Consejo Regulador’s published characterisation of the apple varieties the Asturian designation admits, sorted into nine technological blocks rather than four English classes, and reported in a unit nothing else on the site uses.
1905–1975
The Long Ashton cider apple table
The acid and tannin figures behind almost every English cider apple classification, compiled from analyses made between 1905 and 1975 — and reaching CiderHQ third-hand, which is stated on every number.
2022–2024
The Three Counties perry pear survey
A modern survey of single-variety perry pear juices from Gloucestershire, Herefordshire and Worcestershire — the first dataset to separate the astringent phenolics from the ones that only brown, and the first to measure the nitrogen.
2017
The USDA-PGRU germplasm characterisation
The largest single-season cider characterisation on the site: forty-seven accessions from the United States national apple collection, twelve properties each, all picked in one autumn.
2002–2017
The WSU Mount Vernon cider cultivar trial
Fifteen seasons of European cider fruit grown in the Skagit Valley, and the clearest evidence CiderHQ holds that a cider apple’s class is a statement about a place as much as about a fruit.
late 1970s
The Geneva finished-cider analyses
The only dataset on the site measured on finished cider rather than on juice, which makes it the clearest demonstration of why that distinction is not pedantry.
2018
The IFPC cider apple juice characterisation
Twelve French cider apple juices measured by the national technical institute in 2018 — the only French institutional dataset CiderHQ has opened, and the evidence that “French cider apple” is not a composition.
2007–2008
The Klosterneuburg Mostbirnen trial
Austrian perry pears analysed over two seasons at the research station’s own orchard — the best measured account of Mostviertel fruit CiderHQ has found, and reported in an acid convention nothing else on the site uses.
1903–1963
The Long Ashton perry pear analyses
Nineteen perry pears analysed at Long Ashton between 1903 and 1963, and for most of the twentieth century the only compositional data on perry fruit that existed.
2012–2013
The Virginia polyphenol characterisation
Twenty apple cultivars — mostly dessert and processing fruit, with Harrison among them — measured by one laboratory in one place with one method, which makes it the cleanest evidence on the site for what separates a cider apple from an eating apple.
1922–1977
Typical English apple juice analyses
A short compilation of dessert and culinary apple juices — the fruit a reader actually has in the kitchen, measured the same way as the cider fruit, which makes it the site’s clearest answer to what a cider apple is not.
What these pages are not
CiderHQ transcribes the figures it can use and explains the programmes that produced them. It does not republish a dataset in bulk, and it does not host anybody’s data. Each page names its source and links to it; where a figure was withheld — because the source printed something impossible, or because its unit is unstated — the page says so and gives the published figure and the reason, rather than quietly dropping it.
The rule the whole evidence layer works to is set out in how evidence is handled. In short: a number is stored in the convention its source published it in, converted never, and grouped only with numbers that measured the same thing the same way.