Compound
Succinic acid
An acid made by the yeast rather than the fruit, which adds a salty-bitter edge to a dry cider and, unlike malic acid, cannot be removed by malolactic fermentation.
Also called Butanedioic acid.
- Class
- Acids
- Formula
- C4H6O4
- How often it matters
- Occasional
What it does in cider
- Is produced during fermentation as a by-product of yeast nitrogen and carbon metabolism, so it appears in every cider regardless of the fruit.
- Adds acidity that survives malolactic fermentation untouched, setting a floor below which a cider’s titratable acidity will not fall.
- Contributes an unusual taste that is described as salty and bitter as much as sour, and which is thought to underlie part of the savoury quality of dry ferments.
- Esterifies slowly to mono- and diethyl succinate during maturation.
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.
- salty
- bitter-sour
- savoury
Distinctive among the acids for tasting salty and bitter as well as sour, which is why it registers as a texture or a savoury note rather than as sharpness.
The structure it moves
| Dimension | What it is |
|---|---|
| Acidity | The sharp, mouth-watering quality that makes a cider taste fresh rather than flat. |
| Body | How much weight and viscosity the drink has in the mouth. |
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.
Succinic acid0.4–0.8 g/L
Villaviciosa, Asturias, Spain, 2001–2002 · 4 samples · HPLC · Suárez Valles, Pando Bedriñana, Fernández Tascón, Querol Simón and Rodríguez Madrera, Food Microbiology 24(1):25–31
A yeast product rather than a fruit one, so the figure reflects the ferment and not the orchard. Traditional pressing gave the higher figures in both harvests, which the authors do not attribute to pressing as such.
An acid yeast makes rather than one the fruit supplies, and the main reason a fully fermented cider is not simply the juice minus its sugar. Measured in grams per litre.
What forms it
Processes that put this compound into the drink, or increase how much of it is there.
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.
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.
Organisms that produce it
Which organism is responsible usually decides whether the compound is a feature or a symptom.
Saccharomyces cerevisiae
The yeast that finishes essentially every cider, whether it arrives in a sachet or from the fruit, the press and the vessel.
Torulaspora delbrueckii
A non-Saccharomyces yeast that ferments further than most of its early-succession neighbours while producing notably little acetic acid.
About Succinic acid
Succinic acid is one of the reliable products of alcoholic fermentation, formed by yeast as it shuttles carbon through parts of the tricarboxylic acid cycle and metabolises glutamate. Every cider has some, in the region of a gram per litre, and the amount depends on the yeast and the nitrogen supply rather than on the apples.
Its importance is that it is chemically inert to the things that change other acids. Malolactic bacteria have no route to it, so a cider that has lost half its malic acid to malolactic fermentation still carries its succinic acid in full. This is why a fully malolactic cider does not go completely flat on the palate, and why measured titratable acidity after malolactic never falls as far as the malic figure alone would predict.
What it tastes like is genuinely odd. Where malic and lactic acid are simply sour, succinic acid is described as salty and bitter at the same time, and in a dry cider with little else going on it contributes to the savoury, faintly briny impression that trained panels report and casual drinkers usually attribute to something else.
Related compounds
Compounds it is formed from, converted into, confused with, or routinely met alongside.
Acids
Malic acid
The acid of apples, which supplies almost all the sharpness a cider has and, through pH, decides how vulnerable that cider is to everything that could spoil it.
Acids
Lactic acid
The softer acid that replaces malic when malolactic fermentation runs, halving the acid a cider carries and changing its texture as much as its sharpness.
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.
Nitrogen compounds
Amino acids
The largest usable nitrogen fraction in apple juice, and the raw material from which yeast builds both its own protein and most of the aroma compounds a cider carries.
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.
- What is malic acid and why does it matter in cider — Malic acid is the acid of apples and supplies almost all the sharpness a cider has. It also sets pH, which decides how well sulphite works and how exposed the cider is to spoilage, so it does far more work than its taste suggests.
- 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.
- Why does cider contain lactic acid — Because malolactic bacteria converted the malic acid into it. Malic acid has two acid groups and lactic acid has one, so roughly half the titratable acidity disappears and the cider tastes softer.
- How does cider ferment — Yeast consumes the sugar in apple juice and produces roughly equal masses of ethanol and carbon dioxide, along with the esters and higher alcohols that give cider much of its aroma. In a wild ferment several yeast species take turns before *Saccharomyces* finishes the job.
- Can you make cider from shop bought apple juice — Yes, provided the juice contains no preservative — check for potassium sorbate or benzoate on the label. Pasteurised juice ferments perfectly well once yeast is added, because pasteurisation removes the organisms but not the sugar.
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.
Peer-reviewed literature on cider fermentation microbiology
Various journals · peer-reviewed literature · registered as competent for this subject
Covers the microbial succession of spontaneous cider fermentation, the role of non-Saccharomyces yeasts in the early stages, malolactic conversion by Oenococcus and Lactobacillus species, and the organisms behind the principal spoilage faults.