Sensory descriptor
Acrid smoke
Harsh, ashy smoke from atmospheric smoke absorbed by the fruit, chemically distinct from microbial smokiness.
Also called Smoke taint, Ashtray, Burnt.
- Aroma family
- Phenolic
- Does it indicate a fault?
- It depends on the style it is met in
What causes it
Where an orchard is exposed to wildfire or agricultural smoke during the growing season, the fruit absorbs guaiacol, 4-methylguaiacol and cresols through the skin and binds most of them as glycosides. These are largely odourless in the fruit and in the juice; fermentation and, more slowly, acid hydrolysis in the finished drink release the free phenols, so a cider can taste sound at pressing and acrid months later. The palate effect is characteristic and unpleasantly persistent — an ashy retronasal finish that outlasts the aroma — and it cannot be blended away at any practical dilution.
There is no level at which this contributes anything, and unlike microbial smoke it is not a matter of style expectation. Because the precursors are bound, measured levels at pressing understate the eventual sensory outcome.
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.
4-Ethylguaiacol
The smoky, clove-like partner of 4-ethylphenol, made by the same organisms from ferulic acid, and the compound that pushes phenolic character from medicinal towards spicy.
Total phenolics
The single number used to summarise everything phenolic in a juice, useful for comparing fruit and misleading whenever it is used to predict how a cider will taste.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
Ripeness assessment
Judging when cider fruit has converted enough starch, loosened enough on the spur and hardened enough for the store to be worth gathering.
Fruit washing
Removing soil, grass, stones and surface contamination from gathered fruit, usually in a water flume, before it reaches the mill.
Juice blending
Combining juices from different cultivars before fermentation so that the blend ferments as a single batch, as against fermenting separately and blending later.
Fining
Adding a reactive agent that binds a target colloid and carries it to the bottom, chosen according to whether the problem is tannin, protein or a phenolic taste fault.
The fault it points at
Meeting this descriptor above a certain intensity is how the fault below is usually noticed first.
Fault
Ashtray, burnt and medicinal character in cider made from fruit exposed to wildfire smoke, which enters the fruit as bound precursors and is released later.
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 Acrid smoke
Smoke taint has become a recognised risk in cider-growing regions subject to wildfire, particularly in Australia, Tasmania and the western United States, and it is one of the few faults introduced entirely before harvest.
It is distinguished from Brettanomyces smokiness by what accompanies it: microbial smoke arrives with sticking plaster and horse blanket, while smoke taint arrives alone, with an ashy palate finish that the phenolic fault does not produce.
Others in the phenolic family
Leather, smoke, sticking plaster, horse, medicinal.
Sticking plaster
The sharp antiseptic-and-adhesive note of 4-ethylphenol, the principal volatile phenol of *Brettanomyces* activity in cider.
Horse blanket
An animal, stable-like note from 4-ethylphenol combined with branched short-chain fatty acids.
Medicinal
A hospital-antiseptic note from volatile phenols, or from chlorophenols formed by chlorine contacting phenolic material.
Smoky
A wood-smoke note from 4-ethylguaiacol, the guaiacyl counterpart of the ethylphenol pathway.
Leather
A dry, tanned-hide note from low levels of volatile phenols over well-polymerised tannin.
Bacon
A savoury smoked-meat note from 4-ethylguaiacol with residual sweetness, met in tannic ciders with Brett character.
Plastic
A synthetic, hot-plastic or crayon note from packaging materials, hose or liner contact.
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.
- Is cider vegan — Cider itself is a plant product, but some producers clarify it with animal-derived finings such as gelatine, isinglass or chitosan. Vegan status therefore depends on the fining regime, which is why some ciders are certified and others are not.
- When are cider apples harvested — In the northern hemisphere the cider harvest runs from about September to November, with late bittersweets such as Dabinett and Vilberie coming in last. Cider fruit is generally picked riper than dessert fruit, and often gathered from the ground.
- What is juice blending
- Does cider contain antioxidants — Cider carries apple polyphenols, and tannic bittersweet ciders carry considerably more than pale ones made from dessert fruit. What that means for health is a clinical question this site does not adjudicate.
- What is modern american cider like
- Are apples washed before making cider
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.
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.
Cider and perry production technical training material
Peter Mitchell / Cider and Perry Academy · reference work · registered as competent for this subject
Searched again on 2026-08-25 and it remains the one printed source here that a bibliographic check cannot fix, because it is not a published work with an edition. It is course material issued to participants of a training programme, so there is no catalogue record to verify, no ISBN, and no lawful public copy. Its state stays `registered` for that reason rather than through inattention.