Primary fermentation

Related terms

Terms that belong to the same part of the subject, or that this one is routinely confused with.

• Fermentation

  Fermentation

  The conversion of sugar to ethanol and carbon dioxide by yeast, together with the many secondary reactions that occur alongside it and which supply most of a cider’s aroma.

• Fermentation

  Secondary fermentation

  Any fermentation after the primary: the slow finishing of residual sugar, a deliberate refermentation in bottle or tank for carbonation, or a malolactic conversion by bacteria.

• Fermentation

  Attenuation

  The proportion of the original sugar that fermentation has consumed, calculated from the fall in gravity from the starting to the current reading and expressed as a percentage.

• Fermentation

  Lees

  The deposit that settles under a fermenting or maturing cider: dead and living yeast, fruit solids, pectin, tartrate and protein. Gross lees are the coarse first deposit; fine lees are the finer yeast layer that forms afterwards.

• Fermentation

  Racking

  Transferring cider off its sediment into a clean vessel, leaving the lees behind. It is the basic maintenance operation of the cellar and the traditional method of slowing a fermentation.

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.

• 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.

• 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.