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Cider apple

Stembridge Cluster

A Somerset cider apple from Stembridge that sets its fruit in tight clusters, giving heavy crops of small apples.

Also written Stembridge Clusters.

Classification
Bittersweet — Long Ashton classification
Harvest
Mid (Late September to mid October)
Single varietal
Not suited to a single-varietal cider
Blend role
Bulk juice, Bittersweet base
Origin
Stembridge, Kingsbury Episcopi, Somerset
Species
Malus domestica
Vigour
Moderate
Biennial bearing
Markedly biennial — heavy and light years alternate
Keeping
Moderate
Evidence
Analysed in 1 source, watched at 1 trial site

How it is classified

Long Ashton classification

Bittersweet

Low acid, high tannin. The class that has no real equivalent in dessert fruit and that defines West Country cider.

Basis: Below about 0.45% w/v acid and above about 0.2% w/v tannin.

A mild bittersweet on description; no analysis attaches to this cultivar.

Every classification on CiderHQ names its system. Why there is more than one.

What it contributes to a blend

A direction, not a measurement. These bands are the level of resolution the evidence supports, and they say which way adding this fruit pushes a blend rather than what the finished drink will be.

Contribution to a blend, scored 1–5 as a band. The filled segment is the typical value; the paler segments are the range.
AxisTypicalRange
AcidLow
TanninModerate
SugarModerate
BitternessSlight
AstringencyNoticeable
AromaRestrained
BodyMedium
Based on: its recorded classification

Description in Somerset cultivar listings. These bands were authored from description; published analyses of this fruit have since been transcribed onto the record from named trial programmes and are shown above. The bands are not derived from those figures, which is why this profile is marked as classified rather than measured.

Adds mild tannin and bulk juice from a heavy crop of small fruit.

Aroma

No aroma descriptors are recorded for Stembridge Cluster, and for a great deal of cider fruit that is a finding rather than a gap. Bittersweet apples in particular contribute tannin, sugar and body while being close to aromatically mute, and most of what a cider made from them smells of was produced by the fermentation rather than carried in by the fruit. CiderHQ publishes the absence rather than filling the space with descriptors nothing supports.

Put Stembridge Cluster into a blend

Measured analysis

Each figure is shown with where and when it was taken. They are not averaged: the same cultivar grown in another climate genuinely gives different numbers, and collapsing them into one would be the most misleading thing this page could do.

Measured on the fruit

Measured on the fruit itself, before anything was done to it. These figures hold whatever was later made from the juice.

Reported analyses of Stembridge Cluster, by property and source — measured on the fruit
PropertyReadingWhereWhenSource
Fruit diameter57 mm (53–61)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Fruit firmness78.3 N (74.1–82.5)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Fruit weight89 g (72–106)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Starch pattern index8.0 SPIUSDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit

Measured on the juice

Measured on juice as pressed, before fermentation. This is where most cider analysis lives and what the classification schemes are defined on.

Reported analyses of Stembridge Cluster, by property and source — measured on the juice
PropertyReadingWhereWhenSource
Brix11.3 °Bx (11.1–11.6)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Fructose56.6 g/L (24.7–88.5)Not used in comparisons: see note belowUSDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Glucose22.0 g/L (14.4–29.6)Not used in comparisons: see note belowUSDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
pH3.41 pH (2.81–4.01)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Sorbitol7.7 g/L (5.1–10.3)Not used in comparisons: see note belowUSDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Sucrose10.5 g/L (7.7–13.3)Not used in comparisons: see note belowUSDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Titratable acidity5.0 g/L (3.8–6.2)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
Total phenolics930.0 mg/L (900.0–960.0)USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA2017Modern analysisCornell University / USDA-ARS Plant Genetic Resources Unit
How these were measured
  • Mean of the fruit sampled per accession; where a bracket is shown it is one standard deviation either side of the mean, not the observed range. Published to two decimal places and shown at the precision CiderHQ displays for the unit.
  • Mean of the fruit sampled per accession; where a bracket is shown it is one standard deviation either side of the mean, not the observed range.
  • Cornell generic starch–iodine chart, 1–8, where 1 is no hydrolysis and 8 is complete. Mean of replicate fruit; a bracket, where shown, is one standard deviation either side of it.
  • Penetrometer, mean of replicate fruit; a bracket, where shown, is one standard deviation either side of the mean.
  • Refractometer on pressed juice. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
  • Titration to pH 8.1 with sodium hydroxide, reported as malic acid equivalents. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
  • The starting pH recorded by the autotitrator before titration, on juice stored frozen at −80 °C and thawed; the source describes no separate pH measurement. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
  • Folin–Ciocalteu assay against gallic acid standards, published in grams per litre of gallic acid equivalent and stored here as milligrams per litre by exact conversion. The source converts these figures to Löwenthal tannic acid equivalents, by a laboratory factor of 1.6, only to sort its accessions into classes; the figure here is the unconverted one.
  • Enzymatic assay (Megazyme). Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
  • D-sorbitol/xylitol assay kit (Megazyme), sorbitol dehydrogenase method. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
  • Glucose, fructose, sucrose and sorbitol: Not used in any distribution, ranking or comparison. This programme’s enzyme-assayed sugars do not reconcile with its own refractometer readings across the collection — for many varieties the sugars add up to more than the Brix reading allows. The figures were checked against the thesis’s own tables in October 2026 and are transcribed exactly: the disagreement is in the published source, which does not say which reading is wrong. Proportions between glucose, fructose and sucrose, which came from one assay, are still used in summary.
  • A chart position, not a quantity. Almost every accession here scored at or near 8, which says the fruit was picked at or past full starch conversion rather than that the cultivars are alike.
  • One harvest at one site. Soluble solids move several degrees between seasons and with crop load.
  • A Folin–Ciocalteu figure counts everything that reduces the reagent, not tannin alone, and is not interchangeable with a Löwenthal permanganate figure for the same juice. Compare this reading with other Folin–Ciocalteu readings in gallic acid equivalents.

Where it sits among the varieties each programme measured

Stembridge Cluster against every other variety the same programme measured the same way. Repeat samples are reduced to their median first, and where a programme published a range and not a single figure the midpoint of that range stands for it. Laboratories disagree on absolute figures more than on order, so the position is the sturdier reading.
ProgrammePropertyStembridge ClusterProgramme medianPosition
The USDA-PGRU germplasm characterisationTitratable acidity as malic5.0 g/L4.1 g/LAbove 31, level with 1, below 14 of the other 46: upper middle
The USDA-PGRU germplasm characterisationpH3.413.64Above 5 and below 35 of the other 40: lowest quarter
The USDA-PGRU germplasm characterisationTotal phenolics930 mg/L980 mg/LAbove 20 and below 26 of the other 46: lower middle
The USDA-PGRU germplasm characterisationBrix11.3 °Bx12.5 °BxAbove 11 and below 35 of the other 46: lowest quarter
The USDA-PGRU germplasm characterisationFruit diameter57.0 mm65.0 mmAbove 6, level with 2, below 38 of the other 46: lowest quarter
The USDA-PGRU germplasm characterisationFruit weight89 g124 gAbove 8 and below 38 of the other 46: lowest quarter
The USDA-PGRU germplasm characterisationFruit firmness78.3 N58.9 NAbove 39 and below 5 of the other 44: highest quarter
The USDA-PGRU germplasm characterisationStarch pattern index8.0 SPI8.0 SPIAbove 20, level with 24, below 0 of the other 44: upper middle

Compare within a study to see where these figures sat among the other cultivars the same work analysed — which is a more robust statement than the figures themselves, because absolute values move between laboratories and the ordering inside one study mostly survives.

Watched in the orchard

What named research programmes recorded about this fruit at their own sites. Bloom, harvest and cropping belong to a place and a run of seasons rather than to a cultivar, so they are reported site by site rather than merged.

USDA-PGRU Malus germplasm characterisation

USDA-ARS Plant Genetic Resources Unit, Geneva, New York, in the Finger Lakes region of western New York State · 2017 · Cornell University / USDA-ARS Plant Genetic Resources Unit

Humid continental, with cold winters and warm summers moderated by the Finger Lakes — a sharper seasonal swing than any of the European cider regions whose fruit the collection holds, and warm enough in late summer to bring acid down faster than a maritime autumn does.

Held as
PI 589692, held as “Stembridge Cluster”

One harvest season. Fruit assessed for weight, diameter, starch pattern index on the Cornell 1–8 chart and flesh firmness by penetrometer; juice pressed and measured for soluble solids by refractometer, titratable acidity by titration to pH 8.1 as malic acid, pH as the autotitrator’s starting reading on juice that had been frozen, total phenolics by Folin–Ciocalteu assay as gallic acid equivalent, and glucose, fructose, sucrose and sorbitol by enzymatic assay.

In the orchard

Harvest window
Mid
Flowering
Not recorded
Vigour
Moderate
Cropping
Markedly biennial — heavy and light years alternate
Keeping
Moderate

October. The clustered habit makes hand-picking quick and shaking less effective.

Sets fruit in tight clusters, which gives heavy weight per branch and small individual apples. Thinning is impractical and the tree tends to alternate as a result.

No pollination group is recorded.

Disease and pest susceptibility

Recorded susceptibility. Pressure differs enormously by region and by season, so these are tendencies rather than predictions.
IssueSusceptibilityNote
Scabmoderate—

Juice and pressing

How it is used

On its own

Not suited to a single-varietal cider

A bulk fruit.

About Stembridge Cluster

Stembridge Cluster is named for how it fruits: tight bunches of small apples along the branch rather than well-spaced individuals. That habit gives heavy crops by weight and makes thinning impossible, which is part of why the tree alternates.

A high proportion of skin to flesh has a real consequence for the juice, since apple phenolics are concentrated in and just under the skin. Small clustered fruit therefore tends to give more tannin per litre than its size suggests, though nothing has been measured for this cultivar and the point is a general one rather than a claim about it.

Names, origin and identity

Cultivar naming is the hardest problem in cider fruit data. The same tree carries different names across ten miles, and two different trees have shared a name for two centuries.

Origin · traditional account

Named for the hamlet and for the tree’s clustered fruiting habit. The origin is otherwise unrecorded.

Related cultivars

Recorded relationships, including the ones this fruit is routinely confused with.

Fruit that plays a similar part

Cultivars sharing a classification under the same system and a comparable role in a blend. Not a similarity score — a stated relationship.

Where it grows

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.

Where to go next

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.

Research Evidence standard for this record. What that means.