ISO 712:2009

Overview - ISO 712:2009 (moisture content, cereals)

ISO 712:2009 specifies a routine reference method for determining the moisture content of cereals and cereal products. The method applies to wheat, rice (paddy, husked and milled), barley, millet (Panicum miliaceum), rye, oats, triticale and sorghum - in grain, milled grain, semolina or flour. It is not applicable to maize and pulses (see related standards below).

This standardized procedure is widely used in food testing and quality control to produce comparable, defensible moisture results for trade, storage and process control.

Key topics and technical requirements

• Principle: Test portion is dried at 130 °C–133 °C to produce results equivalent to the absolute method (Annex B).
• Test portion: Rapidly weigh about 5 g ± 1 g into a pre-dried dish; two independent determinations are required.
• Drying times: Typically 120 min ± 5 min (90 min for flours); shorter drying (60 min ± 5 min) may be used in hot, dry climates when validated.
• Apparatus:
  • Analytical balance with ±0.001 g accuracy.
  • Grinding mill that does not absorb moisture, is airtight, minimizes heat generation (temperature rise ≤ 5 °C) and produces the particle size specified in Table 1.
  • Non‑corrodible or glass dishes, oven (130–133 °C) with controlled ventilation and capacity to regain temperature within 30 minutes after loading, and a desiccator.
• Sample preparation:
  • Some products meeting Table 1 particle-size criteria do not require grinding.
  • Products outside those size limits must be ground; preconditioning is required when moisture is >15% (pre-dry) or <9% (bring to 9–15%) to avoid moisture change during grinding.
• Calculation & expression:
  • Moisture content is expressed as g H2O per 100 g product; results are averaged (two determinations meeting repeatability) and rounded to two decimal places.
• Precision:
  • For 10–18% moisture range: repeatability limit r ≈ 0.12 and reproducibility limit R ≈ 0.45 (absolute % points).

Applications and users

ISO 712:2009 is used by:

• Grain testing laboratories and accredited analytical labs
• Millers, cereal processors and food manufacturers (QC and process control)
• Grain traders and commodity inspectors (contract testing)
• Storage and logistics operators monitoring drying and storage condition compliance
• Regulatory authorities and standards organizations for compliance testing

Practical uses include acceptance testing, moisture monitoring for safe storage (mold/spoilage risk), process validation and reporting moisture for trade.

Related standards

• ISO 24333 - recommended sampling for cereals
• ISO 6540 - moisture determination in maize
• ISO 24557 - moisture determination in pulses
• ISO 3310-1 - test sieve specifications (particle-size references)

Keywords: ISO 712:2009, moisture content, cereals, reference method, drying, grinding, laboratory method, cereal testing.