Compound
Shikimic acid
A trace acid that matters less for what it does in the glass than for what it is on the way to: every phenolic compound in cider is built through the pathway named after it.
- Class
- Acids
- Formula
- C7H10O5
- How often it matters
- Specialist — met in particular circumstances
What it does in cider
- Occupies a central position in the shikimate pathway, by which plants make the aromatic amino acids phenylalanine and tyrosine.
- Leads, through phenylalanine, to cinnamic acid and from there to every hydroxycinnamic acid, flavan-3-ol and procyanidin in the fruit.
- Is present in apple and pear juice only in small quantity, and contributes negligibly to taste.
- Is used analytically as one of several compositional markers when the identity of a fruit juice is in question.
About Shikimic acid
Shikimic acid is the hinge of plant aromatic chemistry. Sugar from photosynthesis enters the shikimate pathway, passes through shikimic acid, and emerges as phenylalanine and tyrosine. Phenylalanine is then deaminated to cinnamic acid, and from cinnamic acid the fruit builds p-coumaric, caffeic and ferulic acids, the flavan-3-ols catechin and epicatechin, and the procyanidin polymers assembled from them.
That lineage is the reason a compound present at trace concentration is worth a record. The bitterness and astringency of a bittersweet apple, the browning of cut flesh, the leather note a Brettanomyces infection produces and the rose note the yeast makes from phenylalanine all trace back through this one pathway. A cultivar that is a heavy phenolic producer is one that pushes more carbon down it.
In the glass, shikimic acid does effectively nothing. Its practical appearance in cider work is analytical, as one of the compositional fingerprints used to check whether a juice is what it is said to be.
Related compounds
Compounds it is formed from, converted into, confused with, or routinely met alongside.
Acids
Quinic acid
The second acid of apple juice, better known as the part of chlorogenic acid that is not caffeic acid, and a small but real contributor to the astringent grip of cider fruit.
Phenolics
Hydroxycinnamic acids
The family of small phenolic acids that browns a juice, and whose release from their esters supplies the raw material for every volatile phenol a cider can develop.
Phenolics
Chlorogenic acid
The most abundant single phenolic in apple juice, the preferred substrate of the enzyme that browns it, and the precursor of one of the volatile phenols behind farmyard character.
Phenolics
Procyanidins
The condensed tannins of cider fruit, whose chain length — not their quantity — decides whether the mouth registers bitterness or astringency.
Phenolics
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.
Nitrogen compounds
Amino acids
The largest usable nitrogen fraction in apple juice, and the raw material from which yeast builds both its own protein and most of the aroma compounds a cider carries.
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 are procyanidins in cider — They are the condensed tannins of apples: chains of catechin-type units whose length decides how much of the phenolic load reads as bitterness and how much as astringency. Two ciders with identical total tannin can taste nothing alike.
- 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 chlorogenic acid in apple juice — It is the most abundant hydroxycinnamic acid in apples and the main substrate for enzymatic browning, so it is largely responsible for how brown a pressed juice goes and how quickly.
- What is quinic acid
Where to go next
- All compounds — Grouped by what the fruit brings and what the ferment makes of it.
- Sensory — Every descriptor, with the compound or process that causes it.
- Microbiology — The organisms whose metabolism most of this chemistry belongs to.
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 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 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.