Sensory descriptor
Blackcurrant
A dark, slightly green berry note from sulphur-containing thiols, or from direct fruit addition.
Also called Cassis.
- Aroma family
- Berry
- Does it indicate a fault?
- It depends on the style it is met in
What causes it
The defining blackcurrant volatile is 4-methyl-4-sulphanylpentan-2-one, a thiol with an exceptionally low odour threshold that also carries the boxwood and cat-urine notes at higher concentration. In cider it arises from the same yeast β-lyase route that releases the grapefruit and passion-fruit thiols, from bound cysteine precursors present in the fruit. It is uncommon, requires a thiol-expressive strain, and disappears rapidly on oxygen exposure. In fruit ciders the note is added directly along with the fruit.
The same thiol that gives blackcurrant at trace level gives cat urine and blackcurrant-leaf notes as it rises, and drains as it oxidises. This is the compound class where the gap between fruit and fault is narrowest in the whole lexicon.
The compounds responsible
Where the molecule is established. Some descriptors in this lexicon name a compound the compound register does not yet hold a record for; those are named in the cause above instead.
Mercaptans
What hydrogen sulphide becomes if it is left alone: onion, garlic and rubber notes that are far harder to remove than the gas they came from.
Sulphur dioxide
The antimicrobial and antioxidant on which most modern cidermaking depends, and whose effectiveness collapses as pH rises — which makes every sulphiting decision a pH decision first.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
Yeast selection
Choosing which cultured strain to pitch, on the basis of the temperature, nitrogen, alcohol and aroma behaviour that separates one commercial yeast from another.
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.
Fruit addition
Bringing fruit other than apple or pear into a cider as juice, purée, whole fruit or concentrate, where the timing of the addition decides whether you keep the aroma or the alcohol.
Sulphiting
Adding sulphur dioxide to juice to suppress spoilage organisms and oxidative browning, at a level that only means anything once the juice pH is known.
Where it is usually met
Fruit and styles this character is recorded in. A record here is where the descriptor is commonly found, not a claim that every example shows it.
About Blackcurrant
Blackcurrant is a rare descriptor in unfruited cider and should be recorded carefully, since a panel that means the leaf rather than the fruit is describing something on the other side of the threshold.
In a fruit cider the word carries no mechanistic content beyond the addition itself, and the label rather than the glass is the source of that information.
Others in the berry family
Strawberry, raspberry, red-fruit notes.
Raspberry
A raspberry aroma arising in unfruited cider from bacterial spoilage — the French *framboisé* — as well as from added fruit.
Red fruit
A general soft red-berry impression from medium-chain ethyl esters, most often met in tannic ciders with some age.
Strawberry
A soft red-fruit note from furanone and ester chemistry, arising in fermentation or from added fruit.
Cherry
Dark stone-and-berry character combining benzaldehyde with heavier ethyl esters, met in aged tannic cider.
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 yeast should i use for cider — CiderHQ does not recommend brands. The choice is between a neutral, reliable strain that lets the fruit show, an aromatic wine strain that adds its own esters, and no addition at all. Alcohol tolerance, cold tolerance and nitrogen demand are the properties worth comparing.
- Does cider contain sulphites — Most does. Sulphur dioxide is added to protect juice and finished cider, and fermentation itself produces a small amount even when none is added. European labels must declare it above 10 mg per litre.
- 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.
- Why is sulphite added to cider — Sulphur dioxide suppresses spoilage bacteria and wild yeast before fermentation and protects the finished cider from oxidation. How much of it is active depends strongly on pH, which is why low-acid juice is harder to protect.
- What is fruit cider — Fruit cider is cider flavoured with another fruit, either as juice, purée or flavouring, added after fermentation. How much apple has to remain varies by jurisdiction, and in some markets very little does.
- How is fruit cider made
Where to go next
- The sensory model — The thirteen structural dimensions and the twenty aroma families, in full.
- Compounds — The chemistry behind the words.
- Troubleshooting — When a perception turns out to be a problem, this is where it is diagnosed.
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.
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.
Washington State University cider research programme
Washington State University Northwestern Washington Research and Extension Center · university · passage verified 2026-08-24
The single most useful open cider dataset CiderHQ has found. The programme’s cultivar performance database gives juice chemistry, orchard behaviour, bloom and harvest timing and cider-maker tasting notes for 73 cultivars grown at one maritime site over fifteen years, and — unusually — publishes its classification thresholds alongside its figures, so the classification can be checked rather than taken on trust. It also states outright that its results diverge from the English ones. Read in full on 2026-08-24 and transcribed into `data/trials/wsu-mount-vernon.ts`; four published figures were found to be impossible and are withheld there with their reasons.
Food labelling and packaging guidance
Food Standards Agency / Department for Business and Trade · regulator · retrieved 2026-08-24