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
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.