ISO 6000:1981

Overview

ISO 6000:1981 provides practical guidance for the outdoor storage of round-headed cabbage (Brassica oleracea var. capitata, white and red). The standard covers pre-harvest and harvest measures, drying and handling, construction and operation of clamps (temporary outdoor silos), and monitoring and termination of storage to maintain quality for consumption or industrial use. Annex A lists recommended long-keeping varieties; Annex B discusses the influence of production area and unforeseen storage difficulties.

Key topics and technical requirements

• Harvesting and preparation
  • Harvest in dry weather at temperatures below 10 °C; stop irrigation at least 15 days before harvest.
  • Cut stems 1–2 cm below outer leaves; remove dead or damaged outer leaves.
  • Dry harvested heads in a ventilated frost‑protected area 36–48 hours if needed to reduce brittleness and disease risk.
• Suitability and sizing
  • Store whole, sound, clean, undamaged heads; ideal mass ~2–2.5 kg.
  • Late cultivars and cabbages from light/semi-compact soils are generally better for storage.
• Clamps and ventilation
  • Types: underground clamps, soil-surface clamps, with or without ventilation channels.
  • Ventilation options: horizontal channels (20–30 cm internal dimensions) or vertical channels (15–20 cm, 150–180 cm high). Channel spacing guidance provided.
  • Clamp dimensions and layout guidance (width, height, length) are given as informational ranges rather than prescriptive values.
• Covering and insulation
  • Foundation: 10–15 cm clean straw layer or open‑work crates.
  • Straw cover 20–25 cm loose over clamp; increase earth/straw thickness when external temperatures fall below freezing.
  • Protect against cracks, gaps, snow and uneven melting-signs of putrefaction.
• Storage environment and monitoring
  • Optimum temperature: 0 to +1 °C; avoid prolonged freezing and temperatures >5–6 °C.
  • Optimum relative humidity: 85–90% (prefer slightly higher).
  • Temperature checks: at least three times weekly in autumn, twice weekly in winter; thermometer introduced to reach the upper surface of heads.
• Sorting and termination
  • Remove and grade carefully by hand; discard heavily diseased or frozen heads. Open clamps and dismantle when putrefaction or prolonged warm conditions occur.

Applications and users

ISO 6000 is directly useful for:

• Farmers and growers planning post‑harvest handling
• Post‑harvest managers and cooperatives designing outdoor storage clamps
• Agronomists and extension advisors issuing practical storage recommendations
• Food industry and processors sourcing long‑keeping cabbage
• Quality inspectors and standards implementers assessing storage practices

Related standards

Guidance was produced by ISO/TC 34 (Agricultural food products). For comprehensive post‑harvest systems, consult other ISO guidance on agricultural product handling and cold‑chain management.