Overview
ISO 8851-1:2004 (IDF 191-1:2004) specifies a routine, gravimetric method for the determination of moisture content in butter. Published jointly by ISO and the International Dairy Federation (IDF), this part of the ISO 8851 series defines the controlled heating and weighing procedure used in dairy laboratories to quantify volatile constituents (moisture) by mass loss. The standard includes apparatus and sample preparation requirements, the heating procedure, result calculation and reporting, and precision data.
Key topics and technical requirements
- Scope: Routine determination of butter moisture content; part of the ISO 8851 series covering moisture, non-fat solids and fat (routine methods).
- Principle: Gravimetric evaporation of volatile constituents from a weighed test portion; moisture is determined from the mass loss after controlled heating.
- Apparatus:
- Analytical balance with 1 mg readability.
- Drying oven thermostatically controlled at 102 °C ± 2 °C.
- Heating apparatus (hot plate, Bunsen/Teclu or spirit burner) and suitable beakers (recommended diameter 60–80 mm, height 50–70 mm).
- Sample preparation & handling:
- Store laboratory samples in airtight containers (recommended 5 °C–14 °C).
- Warm unopened sample to mix to a homogeneous state (typically 24 °C–28 °C; do not exceed 35 °C).
- For combined moisture and non-fat solids determinations, weigh 9.5–10.5 g; otherwise 5–10 g test portions are used.
- Procedure highlights: Heat and agitate the sample to avoid spattering; continue until frothing stops and non-fat solids develop a light brown/yellow-brown colour. When using a hot plate, recommended heating is between 120 °C and 160 °C (with exceptions for specific processes). Cooling and weighing follow heating.
- Results & precision: Results are expressed to one decimal place. Interlaboratory precision: repeatability limit (≈0.31 % absolute) and reproducibility limit (≈0.42 % absolute) are reported for the method.
Applications and users
- Quality control laboratories in dairy processing and butter manufacturing.
- Regulatory and compliance testing for product labelling and composition standards.
- Incoming raw-material inspection and process control (moisture affects shelf-life, texture and yield).
- Research and development teams developing butter formulations or process adjustments.
Typical keywords: ISO 8851-1:2004, butter moisture determination, moisture content of butter, routine method, gravimetric moisture analysis, dairy laboratory methods.
Related standards
- ISO 3727-1 / IDF 80-1 - Reference method for moisture determination in butter.
- ISO 8851-2 / IDF 191-2 - Determination of non-fat solids (routine method).
- ISO 707 - Guidance on sampling of milk and milk products.
- ISO 5725 series - Accuracy (trueness and precision) of measurement methods and results.
Note: The standard includes safety warnings; users should observe laboratory safety practices and regulatory limitations when applying the method.