Comparison
Keeved vs fully fermented
What is keeving, and how does it differ from an ordinary fermentation?
In short
Keeving is a pre-fermentation clarification. Pectin methylesterase, sometimes assisted by added calcium, converts juice pectin to calcium pectate, which forms a gel that rises as a brown cap — the chapeau brun — carrying with it much of the nitrogen, the yeast and the suspended solids. The clear juice is drawn from beneath.
What remains is a juice so poor in assimilable nitrogen that fermentation proceeds very slowly and then stops of its own accord, well before the sugar is exhausted. The residual sweetness in a keeved cider is therefore the fruit’s own unfermented sugar, achieved without adding anything or stopping anything.
A fully fermented cider takes the opposite route: the yeast is allowed the nutrition it needs, the sugar is consumed, and any sweetness in the finished drink is restored afterwards by back-sweetening or is prevented from being lost by arresting the ferment. Keeving is slow, requires suitable low-nitrogen fruit, and fails outright if the juice is too rich.
The two things being compared
Each side described in its own terms first, so the table below has something to hang on.
Keeved cider
Cider from juice clarified by keeving, whose nutrient-stripped ferment stalls naturally leaving unfermented fruit sugar behind.
Fully fermented cider
Cider fermented to dryness with the yeast adequately nourished, with sweetness added back afterwards if it is wanted.
Where they differ
Dimension by dimension. Where a row needs a qualification, it carries one rather than being simplified until it fits.
| Dimension | Keeved cider | Fully fermented cider |
|---|---|---|
| Where sweetness comes from | Fruit sugar never fermented, because the yeast ran out of nitrogen. | Nothing, if left dry; otherwise sugar or juice added after fermentation. |
| Nitrogen | Deliberately removed with the chapeau brun. | Retained, and supplemented where the juice is deficient. |
| Fruit requirement | Low-nitrogen fruit, typically traditional bittersweets from unfertilised orchards. Keeving fails on nitrogen-rich juice. | Any fruit. |
| Speed | Very slow — a keeved ferment runs for months at low temperature. | Weeks, and faster still when inoculated and warm. |
| Reliability | Uncertain. The gel may not form, or may form and collapse. | High. |
| Clarity | Juice is clarified before fermentation begins, so the cider is naturally bright. | Clarity is addressed after fermentation, by racking, fining or filtration. |
| Bottle stability | Residual sugar with viable yeast means a real risk of refermentation, managed by low temperature, tight filtration or a strong bottle. | A dry cider is stable; a back-sweetened one carries the same risk and is usually stabilised. |
| Tradition | Central to Norman and Breton cidre, and used in England and elsewhere. | The default in most of the cider world. |
When Keeved cider is the relevant one
The circumstances in which this is the thing being described, rather than a reason to prefer it.
- The sweetness in the finished cider is unfermented fruit sugar and nothing was added.
- You are describing Norman or Breton practice, or an English producer working in that manner.
- The juice is low enough in nitrogen for the technique to work.
When Fully fermented cider is the relevant one
The circumstances in which this is the thing being described, rather than a reason to prefer it.
- The cider fermented out and sweetness, if present, was restored afterwards.
- The fruit or the timetable does not allow a months-long stalled ferment.
- You are describing most cider made anywhere.
A misconception worth clearing up
This comparison exists partly because of the claim below, which is repeated often enough that most readers arrive holding it.
Keeving is a way of stopping fermentation part-way through.
What is actually the case: Nothing stops it. The nutrients are removed before fermentation starts, so the yeast exhausts what little nitrogen it has and slows to a halt on its own. Arresting a ferment by chilling, filtering or sulphiting is a different technique with a different result.
Related comparisons
Distinctions that turn on the same thing, or that this one is routinely confused with.
Back-sweetening vs arrested fermentation
Both produce a sweet cider, but back-sweetening adds sugar or juice to a dry cider afterwards, while arresting stops the fermentation before the sugar is gone.
Wild vs cultured fermentation
A wild ferment runs on the yeasts already present on the fruit and in the building; a cultured one is started with a selected strain in sufficient quantity to dominate from the beginning.
English vs French cider
Both use tannic fruit, but French practice organises itself around keeving and natural residual sweetness while English practice ferments out and finishes the cider afterwards.
Dry vs sweet
Dryness is about residual sugar, but perceived sweetness also depends on acid, tannin, alcohol, carbonation and, in perry, on sorbitol — so the label and the palate can disagree.
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 is the difference between wild and cultured fermentation in cider — A wild fermentation is carried by the yeasts already on the fruit and in the press house, in a succession of species; a cultured one is started by pitching a single chosen strain. Wild ferments are slower, more variable and can carry aromas a single strain does not make.
- What makes french cidre different from english cider — French cidre is generally sweeter, lower in alcohol and naturally sparkling, because the French tradition arrests fermentation by stripping nutrients from the juice rather than fermenting to dryness. English cider is more often fermented out and then blended or back-sweetened.
- How do cider makers make a cider sweet without it refermenting — Back-sweetening adds sugar to a finished dry cider, which then has to be stabilised or pasteurised or it will referment in the bottle. An arrested fermentation stops before the sugar is gone, by cold, by racking or by keeving, so the sweetness was never added.
- Why does a dry cider sometimes taste sweet — Because dryness is a measure of residual sugar and sweetness is a perception. Acid, tannin, alcohol, carbonation and — in perry — sorbitol all shift where a given sugar level lands on the palate, so a label and a mouthful can honestly disagree.
Where to go next
- All comparisons — The rest of the pairs, grouped by what kind of difference is at stake.
- Glossary — Either term on its own, defined without a second thing to hold it against.
- Learn about cider — The background these pages assume, written from the beginning.
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.
Institut Français des Productions Cidricoles (IFPC)
IFPC · research institute · retrieved 2026-08-24
The French technical institute for cider production. The authority for the French cultivar classification families, for keeving as an industrial process, and for the pectin and nitrogen chemistry that keeving depends on.
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.
Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE)
INRAE · research institute · retrieved 2026-08-24
French national agricultural research. Its Angers programme produced much of the published work on apple procyanidin chain length and on the relationship between polymer size, bitterness and astringency.
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.