Cider apple
Northern Spy
A high-acid New York apple, slow to come into bearing and famously late-ripening, widely used in North American cider blends as the acid component and historically important as a rootstock parent.
Also written Northern Spy, Spy.
- Classification
- Sharp — Long Ashton classification
- Harvest
- Very late (November onwards)
- Single varietal
- Rarely bottled on its own
- Blend role
- Acid lift, Late season
- Origin
- East Bloomfield, Ontario County, New York
- Species
- Malus domestica
- Vigour
- Vigorous
- Biennial bearing
- Markedly biennial — heavy and light years alternate
- Keeping
- Very good — holds in store for weeks
How it is classified
Long Ashton classification
Sharp
High acid, low tannin. Includes both purpose-grown sharps and many culinary apples.
Basis: Above about 0.45% w/v acid and below about 0.2% w/v tannin.
Assessed in Fruit grown in New York State trial plantings.
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 cider will be.
| Axis | Typical | Range |
|---|---|---|
| Acid | Very high | |
| Tannin | Negligible | |
| Sugar | Moderate | |
| Bitterness | None | |
| Astringency | None | |
| Aroma | Present | |
| Body | Light |
Cornell acid figures from New York fruit and long-standing commercial use of the cultivar as a juice-acidifying component.
Sharp and clean with a light aromatic lift; the acid arrives first and stays.
Aroma
Descriptors associated with this fruit. Each names a character with a known cause, and association is not a promise — what reaches the glass depends on the ferment as much as on the apple.
- Fresh-cut apple — The smell of a cut apple surface, produced within seconds of the fruit tissue being broken by six-carbon aldehydes released from membrane fats.
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.
| Property | Reading | Where | When | Source |
|---|---|---|---|---|
| Fruit weight2 readings, spanning 155–215 g | 155 g (132–178) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| 215 g | New York State Agricultural Experiment Station, Geneva, New York, USA | late 1970sHistoric analysis | AVI / Van Nostrand Reinhold, New York, 1989, edited by Donald L. Downing (ISBN 0-442-22117-7) | |
| Fruit diameter | 71 mm (67–75) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Fruit firmness | 47.4 N (33.9–60.9) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Starch pattern index | 8.0 SPI | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell 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.
| Property | Reading | Where | When | Source |
|---|---|---|---|---|
| Brix | 12.7 °Bx (10.8–14.6) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Fructose | 72.2 g/L (69.7–74.7) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Glucose | 19.7 g/L (16.4–23.0) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| pH | 3.54 pH (3.46–3.62) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Sorbitol | 6.8 g/L (5.4–8.2) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Sucrose | 39.0 g/L (35.4–42.6) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Titratable acidity | 4.3 g/L (3.9–4.6) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
| Total acid | 0.700–1.000 % w/v | Geneva, New York State | 2010sModern analysis | Cornell University, School of Integrative Plant Science |
| Total phenolics | 1190.0 mg/L (1060.0–1320.0) | USDA-ARS Plant Genetic Resources Unit, Geneva, New York, USA | 2017Modern analysis | Cornell University / USDA-ARS Plant Genetic Resources Unit |
Measured on the finished drink
Measured on the finished drink, after fermentation. Not comparable with the juice figures above: fermentation, fining and time move all of these, and phenolics in particular fall substantially.
| Property | Reading | Where | When | Source |
|---|---|---|---|---|
| pH (finished cider) | 3.38 pH | New York State Agricultural Experiment Station, Geneva, New York, USA | late 1970sHistoric analysis | AVI / Van Nostrand Reinhold, New York, 1989, edited by Donald L. Downing (ISBN 0-442-22117-7) |
| Total acid (finished cider) | 0.700 % w/v | New York State Agricultural Experiment Station, Geneva, New York, USA | late 1970sHistoric analysis | AVI / Van Nostrand Reinhold, New York, 1989, edited by Donald L. Downing (ISBN 0-442-22117-7) |
| Total tannin (finished cider) | 0.048 % w/v | New York State Agricultural Experiment Station, Geneva, New York, USA | late 1970sHistoric analysis | AVI / Van Nostrand Reinhold, New York, 1989, edited by Donald L. Downing (ISBN 0-442-22117-7) |
One property here has been measured more than once. The readings are shown as they were taken and are deliberately not averaged — climate, season, ripeness at picking, the age of the tree and the analytical method all move these numbers, and a single figure would hide every one of them. Where a spread is given below a property, it is the distance between separate studies, not the variation within any one of them.
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 8.2 with sodium hydroxide, reported as malic acid equivalents. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
- Meter on pressed juice before fermentation. Mean of replicates; a bracket, where shown, is one standard deviation either side of the mean.
- Löwenthal permanganate titration, reported by the source as grams per litre of tannic acid equivalent and stored here as milligrams per litre by exact conversion so that it sits in one column with the Folin–Ciocalteu figures the site also holds. The two methods do not measure the same thing and are not interchangeable.
- 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.
- Mean fruit weight as published. The compiler notes that a typical New York dessert apple weighs about 140 g, so most of these are small fruit — which is normal for cider cultivars and is itself the point of the column.
- Titration, reported as malic acid. Analysis of finished cider.
- Meter on finished cider.
- Method not stated by the source, which is a real limitation: different tannin methods give wildly different figures on the same sample.
- Reported as malic acid. Northern Spy holds acid unusually well in store, so a figure taken after two months of cold holding is closer to the picking figure than it would be for most cultivars.
- 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 permanganate figure and a Folin–Ciocalteu figure for the same juice can differ by a factor of two. Compare this reading with other permanganate readings, not with a Folin one.
- Reaches CiderHQ through a transcription of a 1989 food-technology chapter, which itself printed unpublished 1980 work from the station. Unlike the chemistry in this dataset it is a measurement of the fruit rather than of the finished cider, so it is comparable with other fruit weights.
- Measured on finished cider after a spontaneous fermentation, not on juice. It is not comparable with a juice figure for the same cultivar, and the gap between the two is not a disagreement between laboratories — it is what fermentation did.
- Measured on finished cider after a spontaneous fermentation, not on juice. It is not comparable with a juice figure for the same cultivar, and the gap between the two is not a disagreement between laboratories — it is what fermentation did. The compiler notes these tannin figures run at roughly half the Long Ashton juice figures for the same cultivars, and cannot say how much of that is fermentation, how much is Geneva, and how much is method.
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 588872, held as “Northern Spy”
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 8.2 as malic acid, pH by meter, total phenolics by Löwenthal permanganate titration as tannic acid equivalent, and glucose, fructose, sucrose and sorbitol by enzymatic assay.
NYSAES Geneva cider cultivar analyses
New York State Agricultural Experiment Station, Geneva, New York · late 1970s · AVI / Van Nostrand Reinhold, New York, 1989, edited by Donald L. Downing (ISBN 0-442-22117-7)
Humid continental, with a hotter summer and a colder winter than any European cider region. The compiler suggests the growing conditions may be part of why the phenolic figures sit so far below the English ones, and is careful not to claim it.
- Held as
- Listed as “Northern Spy”
Analysis of finished cider after a spontaneous fermentation. Acid by titration as malic; pH by meter; tannin by an unstated method; fruit weight as a mean. The data appear to come from a single season, and the original work was unpublished.
In the orchard
- Harvest window
- Very late
- Flowering
- Not recorded
- Vigour
- Vigorous
- Cropping
- Markedly biennial — heavy and light years alternate
- Keeping
- Very good — holds in store for weeks
One of the last apples picked in New York and Michigan, often into November, which is both its value and its risk in a short season.
Notoriously slow to come into bearing on seedling roots and strongly biennial thereafter.
Keeps until spring and retains acid while doing so, which is why it dominated the American processing trade for so long.
Flowers late and over a long period. North America does not use the English pollination-group numbering, so no group is recorded here.
Disease and pest susceptibility
| Issue | Susceptibility | Note |
|---|---|---|
| Fire blight | moderate | — |
| Apple scab | high | — |
| Woolly apple aphid | low | Its resistance to woolly aphid is why Northern Spy became the parent of the Malling-Merton rootstock series, a contribution to world pomology quite separate from its fruit. |
Juice and pressing
- High malic acid, reliably above the Long Ashton sharp threshold and often well above it.
- Modest sugar, so it lowers a blend’s gravity as it raises its acid.
- Negligible tannin.
- Good juice yield from a large, juicy fruit.
How it is used
- The standard acid component of North American blended cider and of the commercial sweet-cider trade.
- A pie and processing apple across the Great Lakes and New England.
- Used as a breeding parent for disease resistance and as the rootstock parent of the Malling-Merton series.
On its own
Rarely bottled on its own
Thin and severely sharp on its own, with too little sugar to balance the acid. Its role is to be part of something else, and single-varietal bottlings are rare and generally back-sweetened.
About Northern Spy
Northern Spy is the acid apple of the North American cider trade. It ripens very late, keeps until spring, and holds its malic acid through months of storage in a way that most cultivars do not — which means a processor with Spy in store has acid available in March, when it is otherwise unobtainable. That property, rather than any particular distinction of flavour, is why it was planted in quantity from the Finger Lakes to Michigan and why it remains in modern blends.
What it does in a blend is straightforward and one-directional. It raises total acid and lowers pH, which brightens the palate and materially reduces the risk of bacterial spoilage in a juice made mostly of low-acid dessert fruit. It gives nothing else: little sugar, no tannin, modest aroma. Makers use it the way a Somerset blender uses a purpose-grown sharp, with the difference that Somerset had sharps bred for the job and North America had a pie apple that happened to fit.
The tree is difficult. It is slow to come into bearing, strongly biennial, scab-prone, and it drops fruit in a November gale that a shorter-season cultivar would have escaped. Set against that, its resistance to woolly apple aphid was the reason it was used as a parent in the Malling-Merton rootstock breeding programme — so a New York seedling from the 1800s ended up underneath a large fraction of the world’s commercial apple trees.
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.
| Name | Kind | Note |
|---|---|---|
| Red Spy | Regional name | A redder sport, propagated separately in some nurseries but generally treated as the same cultivar for pressing. |
Why it matters
- The default acid supply for North American cider blends built on low-acid dessert fruit.
- Its woolly-aphid resistance made it the parent of the Malling-Merton rootstocks, which shaped commercial apple growing worldwide.
Related cultivars
Recorded relationships, including the ones this fruit is routinely confused with.
Parentage
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.
GoldRush
A scab-resistant Golden Delicious descendant released in 1994, unusually high in both sugar and acid, exceptionally long-keeping, and one of the modern American selections that cider makers actively seek out.
Idared
An Idaho cross of Jonathan and Wagener released in 1942, exceptionally long-keeping and reliably sharp, and one of the most heavily pressed apples in the northern-hemisphere juice trade.
Newton Wonder
A large English dual-purpose apple, sharper than a dessert fruit and sweeter than Bramley, pressed on farms and used in modern blends for acid with some substance.
Porter’s Perfection
A very late Somerset bittersharp with high acid and moderate tannin, cropping heavily in its on years and barely at all in its off ones.
Bramley’s Seedling
England’s dominant cooking apple, a triploid of very high acid and negligible tannin, and by volume one of the most important fruits in modern British cider.
Browns Apple
The standard Devon sharp: a bright red, heavy-cropping, high-acid apple with almost no tannin, and the fruit most English blends reach for when they need lift.
Styles it is characteristic of
New England cider
A strong, dry, oxidative American cider historically raised in gravity with sugar, molasses or raisins and matured in wood, now defined chiefly as a competition category.
Apple wine
A fermented apple drink made to wine strength, usually by raising the starting gravity, and presented and taxed as a wine rather than as a cider.
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.
- How do i balance acid and tannin in a blend — Acid and tannin do different jobs and cannot substitute for each other: acid gives freshness and microbiological safety, tannin gives structure and length. A blend short of acid tastes flabby however tannic it is.
- How do you blend cider
- Is baldwin good for cider — It is one of the New England heritage apples most used for cider, and was measured on finished cider at Geneva in the late 1970s at 0.74 per cent acid and pH 3.32 — sharp, with a low pH that makes it useful in a blend as well as on its own.
- What does fresh-cut apple mean in a cider tasting note — The smell of a cut apple surface, produced within seconds of the fruit tissue being broken by six-carbon aldehydes released from membrane fats.
- How long can apples be kept before pressing
- What is juice blending
Where to go next
- How cider apples are classified — Why there are four schemes and none of them is universal.
- The blend explorer — See which way changing the proportions moves a blend.
- Blending — What a cider maker is actually deciding when they build a blend.
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.
Cornell Cider Research and Extension programme
Cornell University, School of Integrative Plant Science · university · passage verified 2026-08-24
Runs cultivar trials in New York State and publishes juice chemistry for European cider varieties grown in a North American climate — the single most useful counterweight to treating English figures as universal.
Cider, Hard and Sweet: History, Traditions, and Making Your Own
Ben Watson, The Countryman Press, first edition 1999; third edition 2013 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against Open Library: first published 1999 by The Countryman Press, with five editions recorded and a 2008 printing scanned by the Internet Archive as ciderhardsweethi0000benw. The scan is access-restricted to the print-disabled collection. The site had registered this without a year; it now carries one, and the first-edition date matters because a general trade book on cider written in 1999 predates almost the whole of the North American cider revival it is sometimes cited about.
GRIN-Global germplasm database — Malus and Pyrus
United States Department of Agriculture, Agricultural Research Service · research institute · retrieved 2026-08-24
NIAB (incorporating East Malling Research)
NIAB · research institute · retrieved 2026-08-24
East Malling developed the M-series apple rootstocks that determine tree size in essentially every modern orchard, cider orchards included. The authority CiderHQ uses for rootstock behaviour.
Research Evidence standard for this record. What that means.