History · Early to mid twentieth century

Where the bittersweet classification came from

Why are cider apples called bittersweet and bittersharp?

In short

Because a research station in Somerset sorted them that way. Long Ashton analysed pressed juice for total acid and for tannin, set a threshold on each, and placed every fruit in one of the four resulting quadrants: sweet, sharp, bittersweet and bittersharp.

The scheme exists to answer one question — what will this fruit contribute to a blend — and it answers that question well. It was never designed to describe a finished cider, to rank quality, or to classify fruit grown in another climate, and it does none of those things reliably.

Two measurements, four boxes

The scheme rests on two numbers taken from pressed juice: total acid, conventionally reported as malic acid, and total tannin. Long Ashton set the acid threshold at roughly 0.45% w/v and the tannin threshold at roughly 0.2% w/v, and the four classes follow mechanically from which side of each line a fruit falls.

The choice of those two axes was not arbitrary. Acid and tannin are the two things cider apples vary in that dessert and culinary fruit largely do not, and they are the two that determine whether a juice will ferment to something balanced, flabby or undrinkable. Sugar matters too, but sugar is easy to measure by gravity and varies less usefully between cider cultivars.

The thresholds themselves came from the distribution of the fruit actually analysed. They are descriptive cut-offs fitted to a population of English cider apples grown in Somerset, not constants of nature, and a fruit sitting near a line can legitimately be placed on either side of it by different sources in good faith.

The four Long Ashton classes and what each contributes to a blend
Class	Acid	Tannin	What it brings
Sweet	Below about 0.45% w/v	Below about 0.2% w/v	Fermentable sugar, alcohol and softness; little structure or freshness
Bittersweet	Below about 0.45% w/v	Above about 0.2% w/v	Bitterness, astringency, body and ageing capacity — the West Country backbone
Sharp	Above about 0.45% w/v	Below about 0.2% w/v	Acid lift and a lower pH, which also reduces spoilage risk
Bittersharp	Above about 0.45% w/v	Above about 0.2% w/v	Structure and freshness from one fruit; the usual home of single-varietal cultivars

What it was built to do

The scheme is a blending instrument. A maker with tanks of juice from twenty orchards needs to know, quickly and before fermentation, which of them will supply tannin and which will supply acid, so that the finished blend is neither flat nor harsh and sits at a pH low enough to be safe.

That is why the categories are expressed as contributions rather than as flavours. A bittersweet is not a description of how the cider will taste; it is a statement that this juice will push a blend towards tannin and away from acid. Used that way, the classification is genuinely predictive.

It also gave the industry a shared vocabulary at exactly the moment it needed one. Contract growing requires buyer and grower to mean the same thing by a variety’s character, and a four-word scheme backed by laboratory numbers did that job better than the descriptive language of the pomonas it replaced.

What it cannot tell you

It does not measure the distribution of tannin. Total tannin says nothing about the chain lengths of the procyanidins present, and it is that distribution, not the total, that decides how much of the effect is felt as bitterness and how much as astringency. Two fruits with the same tannin figure can behave quite differently on the palate.

It does not travel. The thresholds were fitted to fruit grown at one site in a cool maritime climate. The same cultivar grown somewhere warmer commonly ripens to lower acid and can cross the sharp–sweet boundary, which is why North American and continental programmes that publish the numbers rather than the class are doing something sensible.

And it is silent on almost everything else that matters: aroma, sugar level, assimilable nitrogen, fermentation behaviour, keeping quality. A cultivar’s Long Ashton class is one line of a description, not the description.

Never a universal standardThe four-way split is one national scheme among several. The French families and the Asturian classification cut the same fruit differently on thresholds fitted to their own populations, and a cultivar can sit in different boxes under two systems without either being wrong. CiderHQ names the system in every classification statement for this reason.

How it reached general use

The classification spread because it was useful to the people buying fruit, and because it was carried into print by pomologists who had worked at the station. Liz Copas’s descriptions of West Country cultivars are the principal bridge between the analytical work and the practical orchard language most growers actually use.

From there it entered general cider writing, competition frameworks and product labelling, often detached from the thresholds that define it. A great deal of published use of the word bittersweet carries no measurement behind it at all and means simply low-acid, tannic cider fruit.

That looseness is worth knowing about rather than deploring. The terms remain the most efficient shorthand available in English for what a cider apple does in a blend, provided the reader remembers that they are a Somerset laboratory’s categories and not a property of the fruit.

How this developed

Certainty is marked on each entry. Where the popular account runs ahead of the evidence, that is said rather than smoothed over.

Nineteenth century
Description without measurement
Pomonas and nursery lists describe cider fruit in narrative terms, with no shared or quantitative basis for comparison.
From 1903
Systematic juice analysis
Long Ashton analyses pressed juice from its cultivar collections for acid, tannin and sugar across successive seasons.
Early to mid twentieth century
The four-way scheme
Thresholds of roughly 0.45% w/v acid and 0.2% w/v tannin divide the analysed fruit into sweet, sharp, bittersweet and bittersharp.
Later twentieth century· probable
Adoption and detachment
The terms pass into general cider writing, competition categories and labelling, often without the measurements that define them.

Also answered on this page

Questions this page covers, so you can tell at a glance whether it is the one you want.

What does bittersweet mean for a cider apple?
Who decided the cider apple categories?
Do French cider apples use the same classes?

Places

What people ask next

Questions readers ask about the things this page mentions. Each one goes to the section that answers it rather than to a page written to receive the question.

What is dabinett — The most widely planted English cider apple: a late bittersweet with soft, full tannin that ferments into a cider needing very little added to it. Long Ashton measured it at 0.18 per cent acid and 0.29 per cent tannin.
What was long ashton research station and why does it matter to cider — The National Fruit and Cider Institute opened at Long Ashton, near Bristol, in 1903, to apply laboratory analysis to an industry that had until then run entirely on custom. It became part of the University of Bristol, was renamed Long Ashton Research Station, and worked on cider fruit, juice chemistry, fermentation and orchard practice for most of the twentieth century.
What is kingston black — Kingston Black is a Somerset bittersharp with an unusual balance of acid and tannin, long regarded as capable of making a complete cider unblended. It is difficult to grow well, which is why it is scarcer than its reputation suggests.
Who decided cider apples are bittersweet or bittersharp, and does everyone use the same system
What is juice blending
What is herefordshire cider

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.
A Somerset Pomona: The Cider Apples of Somerset
Liz Copas, The Dovecote Press, 2001. ISBN 9781874336877 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against Open Library: Liz Copas, The Dovecote Press, 2001, ISBN 9781874336877. The author was Long Ashton’s cider pomologist, which is why this work is registered for Somerset cultivar identity at all — it is the nearest thing to a successor to the station’s own descriptions. No copy was opened. Not digitised in any open collection.

Where to go next

The history of cider — The rest of the history, by period and by tradition.
Cider culture — What survived from this history and is still practised.
Regions — The places this happened in, and what they make now.