Storage
Light and cider
Does light damage cider, and is green glass as good as brown?
In short
Light in the ultraviolet and blue part of the spectrum drives photochemical reactions in a bottle, and the effects are fast: hours of direct sunlight can be enough to change a cider noticeably, and days of bright indirect light will do it.
Green and clear glass are not equivalent to brown. Brown glass absorbs strongly across the ultraviolet and blue range, green glass absorbs some of it, and clear glass transmits almost all of it. A clear bottle in a sunlit window is the worst case in normal domestic storage.
The damage cannot be reversed, and it is not the same as ordinary ageing: it produces its own characteristic aromas rather than simply accelerating oxidation.
What light does chemically
The best-characterised light-driven fault in fermented drinks is the reaction that produces prenyl mercaptan in beer, in which riboflavin acts as a photosensitiser: it absorbs light energy and passes it on to other molecules, initiating radical reactions that generate strongly smelling sulphur compounds at very low concentration. Cider does not contain the hop-derived precursors that make beer’s version so distinctive, but it does contain riboflavin and sulphur compounds, and analogous photosensitised reactions occur.
Alongside that, light drives generalised oxidative reactions. Photochemically generated radicals attack phenolic compounds and aldehydes, browning the cider and producing the same family of stale, cardboard and bruised-apple characters that thermal oxidation produces, but in a fraction of the time.
Pinking is a related and distinct effect: some ciders, particularly those from certain cultivars, develop a pink or salmon cast under light exposure through a reaction involving phenolic compounds. It is a colour change rather than an aroma fault, and it is not harmful, but it is a visible sign that a bottle has been in the light.
The mercaptan-type compounds involved have extremely low detection thresholds — parts per trillion in the beer case — which is why a short exposure produces an effect out of proportion to the energy involved.
Glass colour is not decoration
| Glass | Ultraviolet and blue transmission | Practical protection |
|---|---|---|
| Brown or amber | Strongly absorbed across UV and blue | The best commonly available protection; the reason brewers use it |
| Dark green | Partial absorption; more blue light passes than with brown | Meaningful but incomplete; not a substitute for keeping the bottle dark |
| Pale or antique green | Substantially more transmission than dark green | Limited |
| Clear or flint | Nearly all transmitted | Effectively none; contents depend entirely on where the bottle is kept |
| Bag-in-box, keg, can | Opaque | Complete, for as long as the container is intact |
What kind of light, and how much
Direct sunlight is the most damaging by a wide margin, because it is intense and rich in ultraviolet. A bottle in a sunlit window can change perceptibly within hours, and a clear bottle can be badly affected within a single sunny afternoon.
Bright indirect daylight is slower but cumulative, and a bottle kept on an open shelf in a well-lit room for months has received a substantial dose. Fluorescent lighting emits some ultraviolet and is a real if slow contributor; ordinary LED lighting emits very little ultraviolet and is much less of a concern, though blue-rich white LEDs are not entirely neutral.
Because the effect is cumulative and irreversible, the question is total exposure rather than peak intensity. A cider that spends its life in a closed cupboard and is carried through a lit room twice has nothing to worry about.
Practical consequences
- Keep bottles in the case, box or carton they arrived in; it is free light protection and it is already in the house.
- Treat a clear or pale-green bottle as requiring darkness, not merely benefiting from it.
- Do not store cider on an open kitchen shelf, on a windowsill, or in a glass-fronted cabinet in a lit room.
- When buying, be wary of a clear bottle that has been standing under bright retail lighting or in a window; the damage happens before purchase.
- A lightstruck cider cannot be recovered by chilling, decanting or waiting; the reaction products are stable.
Also answered on this page
Questions this page covers, so you can tell at a glance whether it is the one you want.
- Does sunlight ruin cider?
- Is green glass as good as brown for cider?
- Why has my cider turned pink?
Related
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 temperature should cider be stored at, and how much does a warm cupboard actually cost — A cool, stable 8–14 °C is the target for almost every cider and perry, and stability matters at least as much as the number: repeated cycling between warm and cold does more harm than a steady temperature a few degrees above ideal.
- Does cider need to be kept out of the light — Yes, particularly in clear or green glass. Light reacts with riboflavin and sulphur compounds to produce a skunky aroma within hours of direct sunlight.
- Why has my cider turned pink — Pinking is an oxidative colour change in phenolic compounds, usually appearing after a cider is exposed to air or after fining. It affects appearance far more than flavour.
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 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.
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.
Peer-reviewed literature on apple phenolics and cider sensory perception
Various journals · peer-reviewed literature · registered as competent for this subject
Registered as a class rather than as one paper, because the mechanisms CiderHQ describes — tannin chain length driving the split between bitterness and astringency, salivary protein precipitation, enzymatic browning — are established across many studies rather than resting on any single one. Individual papers are cited where a specific number is quoted.
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.