Compound
Sucrose
The disaccharide of apple juice and the sugar most often added to it, split into glucose and fructose by the yeast’s own invertase before any of it is fermented.
Also called Table sugar, Saccharose.
- Class
- Sugars
- Formula
- C12H22O11
- How often it matters
- Regularly encountered
What it does in cider
- Occupies a variable share of juice sugar that falls during storage, because the fruit’s own invertase keeps hydrolysing it to glucose and fructose after harvest.
- Is hydrolysed by yeast invertase outside the cell before uptake, so it never ferments as sucrose and confers no fermentation advantage or penalty of its own.
- Is the standard reference substance for refractometry, which is why Brix is defined on sucrose and reads only approximately on a fruit juice containing three sugars and sorbitol.
- Serves as the conventional addition for chaptalisation and for priming a bottle-conditioned cider, where its clean hydrolysis and known yield make the arithmetic predictable.
How it is perceived
What the compound registers as, and at roughly what concentration. Perception is not a property of the molecule alone: sugar, tannin and carbonation all change where a threshold falls.
- plain sweetness
The reference point against which other sugars’ sweetness is expressed; less sweet than fructose and sweeter than glucose at equal weight.
Descriptors it is responsible for
Sensory records that name Sucrose as a cause. Each states the perception and the mechanism behind it.
- Tinned pear — The syrupy, slightly flat pear character of canned fruit, from heat-degraded pear esters over residual sweetness.
- Mulled spice — The combined clove, cinnamon and citrus-peel character of a mulling blend, always an addition.
The structure it moves
| Dimension | What it is |
|---|---|
| Sweetness | How sweet the drink tastes, which is not the same as how much sugar it contains. |
Measured figures
Shown as they were measured, with the context each was taken in. They are not averaged: a concentration recorded in one country's fruit in one decade is not a constant.
Sugar10.0–30.0 g/L
context not recorded · Sucrose fraction of total juice sugars · Andrew Lea
A moving target rather than a fixed composition. Sucrose hydrolyses steadily in stored fruit, so juice from apples sweated for several weeks carries less sucrose and correspondingly more glucose and fructose than juice from the same fruit milled at harvest.
Fermentable sugar available to yeast, and therefore potential alcohol. Measured in grams per litre.
What forms it
Processes that put this compound into the drink, or increase how much of it is there.
Sugar addition
Adding sugar or apple juice concentrate to raise potential alcohol before fermentation, and the regulatory and compositional consequences of doing so.
Priming
Adding a measured, calculable quantity of fermentable sugar at bottling so that the fermentation which follows generates a predictable volume of carbon dioxide.
Back-sweetening
Adding sugar, juice or concentrate to a cider that has fermented dry — a straightforward adjustment that leaves the drink microbiologically unstable until something is done about it.
What removes or limits it
Processes that reduce it, hold it below a threshold, or stop it forming in the first place.
Wild fermentation
Letting the microflora already present on the fruit and in the press house carry the ferment, in a succession rather than as a single organism.
Inoculated fermentation
Starting a ferment by pitching a chosen yeast culture so that one known strain, rather than the fruit’s resident population, does the work.
Bottle conditioning
Carbonating cider by letting a second fermentation finish inside the sealed bottle, so the gas is generated where it is going to stay.
Faults it is implicated in
Being implicated is not the same as being a fault. Several of the compounds on this site are ordinary constituents of a sound cider and define a named fault only above a concentration.
Bottle over-carbonation
More dissolved carbon dioxide in the bottle than intended or than the glass is rated for — a presentation problem at the mild end and a physical hazard at the severe one.
Gushing
Cider that erupts from the bottle on opening, either because it is over-pressurised or because something in it is nucleating the dissolved gas violently.
Unwanted refermentation
Fermentation restarting in a sealed container, generating carbon dioxide that was not planned for and pressure that a bottle may not withstand.
Starch haze
A persistent haze caused by starch carried in from under-ripe fruit, which has not yet been converted to sugar and stays suspended in the cider.
Under-carbonation
A cider intended to sparkle that has little or no dissolved gas, usually because the bottle conditioning never started or the closure did not hold.
Organisms that produce it
Which organism is responsible usually decides whether the compound is a feature or a symptom.
About Sucrose
Sucrose is glucose and fructose joined together, and nothing ferments it in that form. Saccharomyces secretes invertase into the space outside its cell wall, splits the bond there, and takes up the two monosaccharides separately. The practical consequence is that sucrose added to a cider behaves exactly as an equivalent mixture of glucose and fructose would, minus a small weight gain from the water taken up in hydrolysis.
Its share of juice sugar is not stable. The fruit’s own invertase carries on working after picking, so sucrose falls and glucose and fructose rise through the storage period. Sweating fruit before milling — leaving it in heaps or on slatted racks to soften and lose water — therefore changes sugar composition as well as concentration, and juice from long-sweated fruit is measurably different from juice pressed on the day of picking.
For carbonation the arithmetic is what matters. Fermenting sugar yields close to half its own weight as carbon dioxide, so roughly 4 g/L of sucrose added to a finished cider produces something close to 2 g/L of dissolved CO2 — about one volume, and about one additional bar of pressure at cellar temperature. That is a genuinely useful number, and it is also the number that gets bottles wrong: adding priming sugar to a cider that had residual sugar left in it stacks one fermentation on top of another, and the result is over-pressure rather than a livelier drink.
Related compounds
Compounds it is formed from, converted into, confused with, or routinely met alongside.
Sugars
Glucose
The sugar yeast takes first and the smallest of the three in apple juice, which is why the last sugar left in a slow ferment is almost never glucose.
Sugars
Fructose
The dominant sugar of apple juice and the sweetest of the common sugars, which is why apple juice tastes sweeter than its total sugar figure implies and why a stuck ferment leaves sweetness behind.
Gases
Carbon dioxide
The other product of fermentation, which protects a cider from air while it is being made and, dissolved in the finished drink, changes both its texture and its perceived acidity.
Alcohols
Ethanol
The alcohol yeast makes from fruit sugar, which converts a perishable juice into a keepable drink and carries most of its aroma to the nose.
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 many calories are in cider — Roughly 40 to 60 kcal per 100 ml for most ciders, so a UK pint falls somewhere around 200 to 250 kcal. Alcohol contributes about 7 kcal per gram and residual sugar about 4, so both strength and sweetness matter.
- Why did my cider bottles explode — Because fermentable sugar was still present, or too much priming sugar was used, and the pressure exceeded what the bottle could hold. Never bottle a cider whose gravity is still falling, and never use bottles not designed for pressure.
- Which yeast ferments cider — Saccharomyces cerevisiae finishes almost every cider fermentation, whether it was pitched or arrived from the press house. In a spontaneous ferment it is not the first organism present, only the one that survives the alcohol it makes.
- Where does the fizz in cider come from — Either from fermentation trapped in a sealed container, or from carbon dioxide dissolved into the cider under pressure before filling. The French cider appellations permit only the first, and require at least 1.0 to 1.5 bar at 20 °C depending on the name.
- Which sugar is most of the sugar in apple juice — Fructose, by a long way. Apple juice carries roughly twice as much fructose as glucose, with a smaller amount of sucrose, and fructose is the sweetest of the three on the tongue.
- Why did my sweetened cider start fermenting again — Live yeast met the sugar that was added back. Sweetening is only stable if the yeast has been removed by sterile filtration, killed by pasteurisation, or held in check by sorbate together with sufficient sulphite.
Where to go next
- All compounds — Grouped by what the fruit brings and what the ferment makes of it.
- Sensory — Every descriptor, with the compound or process that causes it.
- Microbiology — The organisms whose metabolism most of this chemistry belongs to.
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.
The Science of Cidermaking and associated technical writing
Andrew Lea · reference work · passage verified 2026-08-24
Written by a food chemist who worked at Long Ashton on apple phenolics. Unusual among specialist cider writing in that it is primary-research-adjacent: the author is describing work he did, and cites the literature. This is why it is registered at tier 1 for chemistry while a general cider book is not.
The New Cider Maker’s Handbook: A Comprehensive Guide for Craft Producers
Claude Jolicoeur, Chelsea Green Publishing, 2013. ISBN 9781603584739 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against the Open Library union catalogue: Chelsea Green Publishing, 2013, ISBN 9781603584739, one edition recorded. That establishes the citation points at a real book in a stated edition, which is what a citation needs and is all it establishes. No copy was opened and nothing is quoted from it. The book itself is in print and not digitised in any open collection; where CiderHQ needs a figure from this territory it uses an accessible research source instead and says so.
Alcoholic Products Technical Guide, section 2 — alcoholic products (formerly Excise Notice 162)
HM Revenue & Customs · regulator · passage verified 2026-08-24
What may be called cider or perry for UK duty purposes. The substantive text now lives in section 2 of the Alcoholic Products Technical Guide rather than in the notice itself, and the passages below were read there. The widely repeated "35% juice" figure checks out — but note two things the figure alone hides: it is a tax threshold rather than a quality standard, and concentrate and dilution both count towards it.