Glossary · Fermentation
Wild fermentation
Also written spontaneous fermentation, natural fermentation. Each is a name for the same thing, which is why none of them has an entry of its own.
Definition
Fermentation by the yeasts already present on the fruit and in the press house, without a cultured inoculation.
- Subject
- Fermentation
- Also written
- spontaneous fermentation, natural fermentation
In more detail
A wild ferment is a succession, not a single organism. Apiculate yeasts such as Hanseniaspora and Metschnikowia start it and contribute much of the early aromatic complexity, then die out as alcohol rises; Saccharomyces takes over and finishes the sugar. Much of what people value in traditional cider comes from that first, short-lived phase.
The trade-off is control. The same population contains spoilage organisms, and a wild ferment that stalls in a high-pH, low-nitrogen juice is where lactic disorders and volatile acidity begin. Producers who ferment wild manage the risk with sound fruit, cool cellars, blending for pH and a pied de cuve.
Where this is covered properly
The glossary defines; these pages explain. Each is described in its own words.
Production
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.
Production
Microbial succession
The ordered handover of a spontaneous ferment from apiculate yeasts to *Saccharomyces* to lactic acid bacteria, and the spoilage organisms waiting at the end of it.
Style
Wild-fermented cider
Cider fermented by the yeast population already present on the fruit and in the cellar, without an added cultured strain.
Related terms
Terms that belong to the same part of the subject, or that this one is routinely confused with.
Fermentation
Pied de cuve
A starter made from the must itself: a small parcel of juice allowed to begin fermenting spontaneously, then added to the main tank to give the native population a head start.
Microbiology
Apiculate yeast
Lemon-shaped, weakly fermenting yeasts — *Hanseniaspora* and its anamorph *Kloeckera* — that dominate the first days of a wild cider fermentation before alcohol suppresses them.
Microbiology
Microbial succession
The orderly replacement of one microbial population by another during fermentation, as rising alcohol, falling sugar, falling nutrient and falling oxygen change which organism can compete.
Fermentation
Inoculation
Adding a selected yeast culture to the juice to conduct the fermentation, usually after rehydrating dried yeast or building a starter.
Microbiology
Yeast
A single-celled fungus that ferments sugar to ethanol and carbon dioxide. Cider is fermented by a succession of yeast species, of which *Saccharomyces cerevisiae* usually finishes the job.
Where to go next
- Cider glossary — The whole vocabulary, by subject and A–Z.
- Comparisons — Terms that are only really clear when set against the thing they are not.
- Search — Finds terms by their aliases and by their spellings in other languages.
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.
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.