Some “cider vinegar” is made from concentrated cider rather than fermented fresh cider; if the label does not state origin and acidity, request the specification sheet.

Because the substance is identical either way, grade and documentation do the real separating: pharmacopoeial vs food vs technical grade, assay basis, impurity limits (heavy metals, residual solvents, water), container size and, for stereochemical names, an optical-purity clause.

Are Apple cider and Cider vinegar chemically identical?

Yes. Both short forms point at the same product: cider vinegar is the UK/trade name, apple cider (ACV) the US shorthand.

Which spelling is correct?

Both are accepted, but in different domains: One half is simply shorthand for the other; the expanded form is what should appear in specifications.

What should a purchase order say?

Name plus CAS plus grade plus quantity. For Apple Cider Vinegar the CAS alone removes every ambiguity created by spelling, shorthand or stereochemistry prefixes.

Is the short form ever a different product?

Yes — and that is precisely why the specification, not the name, decides what ships. One half is simply shorthand for the other; the expanded form is what should appear in specifications.

Editorial note

This article clarifies naming equivalence for procurement and documentation use. It is not legal or regulatory advice; the controlled source for any label is the current monograph, CAS index entry and applicable market regulations.