ISO 22308-1:2021

Overview

ISO 22308-1:2021 specifies a sensory test method for detecting, qualifying and assessing exogenous odours and flavours transferred from cork bark selected as bottling product into contact media (water as a model for beverages) by maceration/soaking. The standard applies to cork bark in all forms and to all cork stopper components (granules, discs, bodies, shanks) and stopper types (semi‑finished, coated, branded or ready for use).

Keywords: ISO 22308-1:2021, cork bark, sensory evaluation, soaking, maceration, cork stoppers, odour detection.

Key topics & technical requirements

• Scope and intent: Detection and organoleptic qualification of odours/flavours exogenous to cork that could affect still and sparkling wines, spirits, beers and ciders.
• Principle: Compare a control solution (water) with the solution after cork maceration to detect differences by smell and, if needed, taste.
• Sample preparation: Specific procedures for whole stoppers, partially inserted stoppers, discs, granules and bar-top corks; flasks/vessels must be inert and odourless; fill to brim and close.
• Maceration conditions: 24 h ± 2 h at 21 °C ± 4 °C; use organoleptically neutral spring water with low minerality.
• Test conditions: Quiet, well‑ventilated, odour‑free room; recommended temperature and humidity (21 °C ± 4 °C; 60 % ± 20 %); panelists should avoid perfumed products.
• Sensory panel: Minimum three selector assessors; individual analysis of each maceration solution.
• Method steps: 1) Olfactory evaluation; 2) Optional gustative evaluation; 3) Individual re‑sniffing of stoppers if alteration detected; 4) Decision and intensity rating.
• Result expression:
  • Odour/flavour families (e.g., Chemical: solvent, phenol; Plant: fresh grass, hay; Earthy/mouldy/reduced families).
  • Classification rule: at least two assessors must detect/qualify an odour in the same family for it to be reported; otherwise report as unqualified.
  • Intensity scale: Level 1 (suspicion) to Level 4 (strong); use arithmetic mean if assessors disagree.
• Reporting requirements: sample ID, sampling method, number of stoppers, results, reference to ISO 22308-1:2021 and any deviations/incidents.

Applications & users

ISO 22308-1:2021 is practical for:

• Cork producers and quality control laboratories validating cork batches.
• Bottling houses, wineries, breweries and distillers checking closure suitability.
• Third‑party testing and sensory labs performing release or complaint analyses.
• Regulatory and conformity assessment bodies concerned with beverage sensory quality.

Using this standard helps prevent off‑flavours in packaged beverages and supports consistent sensory screening of cork materials.

Related standards

• ISO 633 (Cork - Vocabulary)
• ISO 3591 (Wine‑tasting glass)
• ISO 5492 (Sensory analysis - Vocabulary)
• Additional referenced methodologies: ISO 3972, ISO 5496, ISO 6658, ISO 8586, ISO 8589

This summary helps quality managers and sensory scientists implement ISO 22308-1:2021 for reliable detection of cork‑related off‑odours through standardized maceration sensory testing.