ISO 11865-2009 PDF

Full title and description

ISO 11865:2009 — Instant whole milk powder — Determination of white flecks number. Specifies a laboratory method to quantify visible white flecks (undissolved particles) in reconstituted instant whole milk powder by measuring the volume fraction of liquid retained on a fine sieve under defined reconstitution and filtration conditions. Also published jointly as IDF 174:2009.

Abstract

This International Standard defines the White Flecks Number (WFN) test for instant whole milk powder: a reproducible procedure for preparing a sample, reconstituting it under controlled conditions, passing the reconstituted sample through a 63 µm sieve and measuring the retained liquid volume after a fixed time. The retained volume is converted to the WFN value that represents the amount of white flecks affecting reconstitution quality and consumer appearance.

General information

• Status: Published (confirmed on review; current edition).
• Publication date: 24 September 2009 (Edition 2, IDF 174:2009).
• Publisher: International Organization for Standardization (ISO), published jointly with the International Dairy Federation (IDF).
• ICS / categories: 67.100.10 — Milk and processed milk products.
• Edition / version: Edition 2 (2009) — ISO 11865|IDF 174:2009.
• Number of pages: 6 pages (official ISO publication).

Scope

Applies to instant whole milk powder and specifies a standardized laboratory test to determine the White Flecks Number (WFN). The method is intended for quality control, specification compliance and inter‑laboratory comparison where visual reconstitution defects (white flecks) are a concern. It defines sample size, reconstitution temperature and procedure, apparatus (including a 63 µm sieve), filtration timing and calculation of the WFN.

Key topics and requirements

• Definition of White Flecks Number (WFN) and its interpretation in product quality assessment.
• Required apparatus and materials (63 µm sieve, 400 ml beaker, analytical balance, stirrer, stopwatch, measuring cylinders, etc.).
• Sample preparation and specified reconstitution procedure (water temperature, mixing/stirring regimen, total test volume).
• Filtration/settling step and measurement of retained liquid volume after a defined time (basis for WFN calculation).
• Calculation method to convert retained volume to the WFN value and reporting format.
• Precision and repeatability considerations and notes on inter‑laboratory comparability.
• Annexes/notes describing test limitations, interpretation guidance and reference to related test methods (sieving, sampling, precision evaluation).

Typical use and users

Used by dairy product manufacturers, quality assurance and R&D laboratories, processors of instant milk powders, inspection and conformity testing bodies, regulatory agencies and standardization committees. Typical applications include in‑factory quality control, batch release testing, supplier acceptance testing and product specification development.

Related standards

Commonly referenced alongside standards for sampling and test apparatus, for example ISO 707 (sampling of milk and milk products), ISO 3310‑1 (test sieves — metal wire cloth) and ISO 5725 series (precision of measurement methods). The standard supersedes ISO 11865:1995 and is published jointly as IDF 174:2009; national/adopted versions include BS ISO 11865:2009 and other identical national adoptions.

Keywords

white flecks number, WFN, instant whole milk powder, reconstitution, sieve 63 µm, IDF 174, milk powder quality, sieving test, product appearance, QA/QC.

FAQ

Q: What is this standard?

A: ISO 11865:2009 is an international laboratory method that defines how to measure the White Flecks Number (WFN) in instant whole milk powder—an indicator of undissolved particles that affect appearance after reconstitution.

Q: What does it cover?

A: It covers the apparatus, sample preparation, reconstitution and filtration procedure (using a 63 µm sieve), measurement of retained volume after a defined time and the calculation and reporting of the WFN. It is a test method for quality assessment rather than a product performance specification.

Q: Who typically uses it?

A: Dairy manufacturers, QA/QC and testing laboratories, product developers, conformity assessment bodies and regulators involved with powdered milk quality and consumer acceptability assessments.

Q: Is it current or superseded?

A: Edition 2 published in 2009 is the current ISO publication for this method (it replaced ISO 11865:1995). The ISO edition was confirmed on periodic review and remains the active published version.

Q: Is it part of a series?

A: It sits within the suite of ISO standards for milk and milk products (ISO/TC 34/SC 5). It is related to standards on sampling, sieving and test method precision (for example ISO 707, ISO 3310‑1 and ISO 5725 series) and is jointly published with the International Dairy Federation as IDF 174:2009.

Q: What are the key keywords?

A: White flecks number, WFN, instant whole milk powder, reconstitution, 63 µm sieve, IDF 174, milk powder quality.