ISO 17727:2012

Overview

ISO 17727:2012 - "Cork - Cork stoppers for still wine - Sampling plan for the quality control of cork stoppers" defines standardized sampling plans used for incoming and outgoing quality control of ready-to-use cylindrical cork stoppers (flush mouth finish) in semi-worked or finished form. The standard applies specifically to controls performed at receipt or shipment (not in‑process production tests) and is focused on parameters for which an ISO test method exists, including physical, chemical, microbiological and sensory analyses.

Key topics and requirements

• Scope: sampling for still-wine cork stoppers (cylindrical, flush finish); excludes production type/validation tests.
• Batch definition: supplier defines the batch to ensure homogeneity; sample size n chosen to optimize testing needs.
• Packaging rules: procedures for sampling from boxes (outer packaging) and large bags (packaging) - open K boxes/bags and take n/k stoppers per opened pack.
• Hygiene: microbiological sampling (ISO 10718) requires specific hygienic conditions; visual inspection for appearance and defects is performed first.
• Distribution types: distinguishes parameters following normal distribution and random distribution, with different sampling approaches.

Key parameters covered (with sampling guidance from the standard):

• Physical tests (see ISO 9727 series): dimensions (sample 32), apparent density (agglomerate) (20), mass, moisture (20), dimensional recovery (5), extraction force (5), liquid tightness (6), dust content (1×4).
• Chemical tests: oxidizing residues / peroxide residues (1×4) - see ISO 21128.
• Microbiological tests: enumeration of yeasts, moulds and bacteria (1×8) - see ISO 10718.
• Sensory/organoleptic analysis: organoleptic samples (32 or 50 or 64 depending on batch size) - see ISO 22308.
• TCA screening: releasable 2,4,6‑trichloroanisole (TCA) sampling (1×20 up to 3×20 depending on batch size) - see ISO 20752.

Practical applications and users

ISO 17727:2012 is intended for:

• Cork manufacturers and suppliers performing final product release and shipment checks.
• Wineries, bottlers and importers conducting incoming quality control of stoppers.
• Third‑party testing laboratories executing standardized sampling and analyses.
• Quality managers and procurement teams writing supplier specifications and acceptance criteria.

Practical benefits include consistent acceptance sampling, reduced risk of cork-related wine faults (TCA/off‑flavours), assurance of stopper performance (extraction force, tightness), and documented traceability for shipments.

Related standards

• ISO 9727 (Parts 1–7) - physical tests for cylindrical cork stoppers
• ISO 10718 - microbiological enumeration
• ISO 20752 - determination of releasable TCA
• ISO 21128 - oxidizing residues (iodometric titration)
• ISO 22308 - sensory analysis

Keywords: ISO 17727:2012, cork stoppers, sampling plan, quality control, TCA, microbiological analysis, dimensions, extraction force, liquid tightness.