Overview
ISO 20716:2022 - Oolong tea: Definition and basic requirements defines what may be sold as oolong tea and sets basic quality, manufacturing, chemical, packing and marking requirements. The standard specifies the plant parts suitable for oolong (new shoots of Camellia sinensis), key production steps (withering; tumbling and aeration/partial oxidization; enzyme inactivation; shaping; drying), sensory assessment by skilled tasters, sampling and storage. It excludes scented or flavoured teas.
Key topics and requirements
- Definition: Oolong tea is derived exclusively from moderately matured new shoots of Camellia sinensis and produced by acceptable processes that include partial aeration/oxidization.
- Manufacturing process:
- Harvest: new shoot with one bud and two to four leaves.
- Withering: outdoor (sun) or indoor (air flow/heating/dehumidification).
- Tumbling and aeration: repeated cycles bruise leaf edges (typical tumbling ~2–60 min; static aeration ~1–5 h) to develop aroma and oxidation level (light, medium, high).
- Enzyme inactivation: pan-firing at high temperature (about 250–300 °C) to stop enzymatic reactions.
- Shaping: rolling (strip-shape) or wrapping-twisting (globular).
- Drying: to appropriate moisture content.
- Sensory analysis: Quality judged by experienced tea tasters on dry leaf appearance, aroma, liquor colour/taste and brewed leaf; characteristic oolong notes include floral/fruity aroma, mellow taste and sweet aftertaste.
- Chemical requirements: The standard lists laboratory criteria (expressed on oven‑dried basis) used to indicate good manufacturing practice - examples include minimum water extract and thresholds for total polyphenols, catechins, caffeine and theanine. Specific test methods are referenced (e.g., ISO 9768, ISO 14502 series, ISO 10727, ISO 19563).
- Packing & storage: Pack in clean, dry, inert containers; store in clean, odourless warehouses separated from harmful/odorous substances.
- Sampling & test methods: Sampling according to ISO 1839; sample preparation and analytical methods referenced (ISO 1572, ISO 1573, ISO 1575, ISO 15598, etc.).
Applications - who uses ISO 20716:2022
- Tea producers and processors: to design and document oolong manufacturing and quality control.
- Quality managers and lab analysts: to verify chemical criteria and apply referenced ISO test methods.
- Exporters, importers and regulators: to assess compliance, labeling and packing requirements.
- Tea graders and sensory panels: to align sensory evaluation with the standard’s expectations.
- Packaging suppliers and warehouse operators: to meet storage and marking specifications.
Related standards
Keywords: ISO 20716:2022, Oolong tea standard, chemical requirements for oolong tea, oolong tea manufacturing, sensory analysis, packing and marking, tea quality control.