EN ISO 24223:2026

• Abstract:

  This document gives guidance on the sample preparation of milk and milk products for physical and chemical analysis, including analysis by applying instrumental methods.; This document specifies the (sub)sampling and sample preparation steps carried out after sampling in accordance with ISO 707 | IDF 50 [1] and prior to method-specific sample preparations (e.g. as with analytical methods).; NOTE Analysis on volatile substances, minor components or allergens can require additional precautionary measures in sample preparation in order to avoid loss of or contamination with one or more target analytes.

• Status: Not Published
• Publication Date: 10-Nov-2026
• ICS: 67.100.01 - Milk and milk products in general
• ICS: 67.100.30 - Cheese
• Technical Committee: CEN/TC 302 - Milk and milk products - Methods of sampling and analysis
• Drafting Committee: CEN/TC 302 - Milk and milk products - Methods of sampling and analysis
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 19-Mar-2026
• Completion Date: 19-Mar-2026
• Ref Project: oSIST prEN ISO 24223:2026 - Milk and milk products - Guidance on sample preparation for physical and chemical testing (ISO/DIS 24223:2025)

• Consolidated By: ISO 24223:2026 - Milk and milk products — Guidance on sample preparation for physical and chemical testing
• Effective Date: 12-Feb-2026
• Revises: EN ISO 24223:2021 - Cheese - Guidance on sample preparation for physical and chemical testing (ISO 24223:2021)
• Effective Date: 22-May-2024

EN ISO 24223:2026 is the European adoption of ISO 24223:2026, published through CEN, and it gives guidance on preparing milk and milk products for physical and chemical testing. It specifies the subsampling and sample-preparation steps performed after sampling to ISO 707 | IDF 50 and before method-specific preparation, including instrumental analysis, for laboratories working with dairy samples.

What does EN ISO 24223:2026 specify?

EN ISO 24223:2026 covers sample preparation for milk and milk products before physical and chemical testing. The document is aimed at the stage between sampling and the specific analytical method, so the test portion sent to the instrument or wet-chemical method is as representative as possible.

The document is organized into seven clauses: scope, references, terms and definitions, apparatus, sample receipt, procedure, and test report. Clause 6 is the core of the document and is split by product type, with detailed guidance for liquid dairy products, butter and butterfat, concentrated products, dried products, products with solid additives, and cheese.

What are the key requirements of EN ISO 24223:2026?

• Clause 4, apparatus: EN ISO 24223:2026 requires clean, dry laboratory tools that do not change the sample composition. In practice, this means the knife, grinder, blender, sieves, containers, and water bath must not add heat, moisture, contamination, or loss of water-soluble components.

• Clause 5, sample receipt: EN ISO 24223:2026 allows sub-samples from the same batch to be prepared separately or combined into one sample, provided the combined sample is properly mixed. This matters when several containers represent one lot and the lab wants one representative test portion.

• Clause 6.1, general handling: EN ISO 24223:2026 asks for fast handling, minimal exposure to air, and cleaning between samples. That reduces evaporation, adsorption, contamination, and changes in sample structure before testing starts.

• Clauses 6.2 to 6.4, liquid and semi-liquid products: EN ISO 24223:2026 gives product-specific temperature and mixing steps for milk, buttermilk, cream, whey, fermented milk, liquid infant formula, butter, butterfat, evaporated milk, sweetened condensed milk, and concentrated milk products. The practical aim is to redistribute fat, dissolve crystals where needed, and obtain a homogeneous test portion without overheating or separating the emulsion.

• Clause 6.5, dried products: EN ISO 24223:2026 uses sieving as the first check for dried milk, whey products, casein, caseinates, and dried infant formula. If too much remains on the sieve, the sample is ground or blended until the sieve criterion is met, which helps reduce heterogeneity before analysis.

• Clause 6.6, products with solid additives: EN ISO 24223:2026 requires blending so fruit, herbs, spices, olives, nuts, and similar additions are evenly distributed. This matters because the added ingredients can otherwise be unevenly represented in the test portion.

• Clause 6.7 and Tables 1 to 3, cheese: EN ISO 24223:2026 gives cheese-specific steps for draining, removing non-edible outer parts, cutting, grinding or blending, and final preparation. The tables guide what to do for hard, semi-hard, soft, semi-soft, fresh, and processed cheese, so the lab can keep edible material in the sample and still achieve homogeneity.

• Clause 7, test report: EN ISO 24223:2026 requires the report to include ISO/IEC 17025:2017 reporting information, ambient conditions, and a clear description of the sample-preparation steps. This helps users understand exactly how the test portion was prepared and judge whether the result fits the intended use.

What terms does EN ISO 24223:2026 define?

• Cheese surface: the outer layer or outer parts of cheese, including sliced, shredded, or grated forms.
• Cheese coating: a non-cheese layer or film that protects cheese during handling and can also affect presentation.
• Cheese rind: a semi-closed outer cheese layer with lower moisture content that develops during ripening.
• Non-edible part: any part of cheese that is specified as not intended for human consumption.

Who uses EN ISO 24223:2026?

EN ISO 24223:2026 is used by dairy laboratories, analytical chemists, quality managers, and sampling personnel who prepare milk and milk products for physical and chemical testing. It is also relevant to manufacturers, contract laboratories, and food control or compliance teams that need representative test portions for routine quality control, release testing, or dispute work. The document is especially useful where product form affects the result, such as cheese, butter, concentrated products, dried powders, and products with inclusions.

What changed in EN ISO 24223:2026 from the previous edition?

EN ISO 24223:2026 cancels and replaces ISO 24223 | IDF 253:2021. The main change stated for this edition is that the scope was expanded from cheese to other milk and milk products.

Which standards are used with EN ISO 24223:2026?

EN ISO 24223:2026 points users to ISO 707 | IDF 50 for sampling before the preparation steps in this document. It also uses ISO/IEC 17025:2017 for the content of the test report in Clause 7.

The bibliography also names analytical methods that can follow this preparation, including methods for fat content, dry matter, phosphorus, citric acid, copper, chloride, calcium, sodium, potassium and magnesium, organochlorine pesticides and polychlorobiphenyls, nitrogen, and natamycin.

What does the EN ISO 24223:2026 document contain?

EN ISO 24223:2026 contains a general apparatus list, a short rule for receiving and combining sub-samples, and a detailed procedure section organized by product family. Clause 6 includes specific handling for liquid dairy products, butter and butterfat, concentrated milk products, dried products, products with solid additives, and several cheese types. Tables 1 to 3 summarize cheese-related decisions for removing outer parts, cutting, and grinding or blending. Clause 7 sets out what to record in the test report, including ambient conditions and the sample-preparation history.

SLOVENSKI STANDARD
01-januar-2026
Mleko in mlečni izdelki - Navodilo za pripravo vzorcev za fizikalno in kemijsko
preskušanje (ISO/DIS 24223:2025)
Milk and milk products - Guidance on sample preparation for physical and chemical
testing (ISO/DIS 24223:2025)
Milch und Milcherzeugnisse - Leitfaden zur Probenvorbereitung für die physikalische und
chemische Prüfung (ISO/DIS 24223:2025)
Lait et produits laitiers - Lignes directrices pour la préparation des échantillons en vue
des essais physiques et chimiques (ISO/DIS 24223:2025)
Ta slovenski standard je istoveten z: prEN ISO 24223
ICS:
67.100.01 Mleko in mlečni proizvodi na Milk and milk products in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 24223
IDF 253
ISO/TC 34/SC 5
Milk and milk products — Guidance
Secretariat: NEN
on sample preparation for physical
and chemical testing
Voting begins on:
2025-11-26
ICS: 67.100.01
Voting terminates on:
2026-02-18
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference numbers
ISO/DIS 24223:2025(en)
IDF 253:2025(en)
DRAFT
ISO/DIS 24223:2025(en)
International
Standard
ISO/DIS 24223
IDF 253
ISO/TC 34/SC 5
Milk and milk products — Guidance
Secretariat: NEN
on sample preparation for physical
and chemical testing
Voting begins on:
ICS: 67.100.01
Voting terminates on:
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
© ISO and IDF 2025
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
USER PURPOSES, DRAFT INTERNATIONAL
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
BE CONSIDERED IN THE LIGHT OF THEIR
or ISO’s member body in the country of the requester.
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
ISO copyright office International Dairy Federation
NATIONAL REGULATIONS.
CP 401 • Ch. de Blandonnet 8 Silver Building • Bd Auguste Reyers 70/B
RECIPIENTS OF THIS DRAFT ARE INVITED
CH-1214 Vernier, Geneva B-1030 Brussels
TO SUBMIT, WITH THEIR COMMENTS,
Phone: [phone] Phone: [phone]
NOTIFICATION OF ANY RELEVANT PATENT
Fax: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail] Email: [e-mail]
Website: www.iso.org Website: www.fil-idf.org
Reference numbers
Published in Switzerland ISO/DIS 24223:2025(en)
IDF 253:2025(en)
ii
ISO/DIS 24223:2025(en)
IDF 253:2025(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus . 2
5 Sample receipt . 3
6 Procedure . 3
6.1 General .3
6.2 Milk, buttermilk, cream, whey, fermented milk and liquid infant formula .3
6.3 Butter and butterfat.3
6.4 Concentrated milk products .4
6.4.1 Pretreatment in connection with lactose crystals .4
6.4.2 Evaporated milk . .4
6.4.3 Sweetened condensed milk . .4
6.5 Dried milk and whey products, casein, caseinates and dried infant formula .4
6.6 Products with solid additives such as fruit, herbs, etc. .5
6.7 Cheese .5
6.7.1 General .5
6.7.2 Cheese packaged and stored in liquid (e.g. high moisture mozzarella in
governing liquid, cheese in brine, cheese in oil).5
6.7.3 Blue veined cheese (e.g. stilton, gorgonzola, roquefort) .5
6.7.4 Cheese with included additions (e.g. herbs, spices, condiments, olives and nuts) .5
6.7.5 Fresh cheese (e.g. cottage cheese, fromage frais, cream cheese) .5
6.7.6 Cheese - Removal of parts not objective to subsequent analysis .6
6.7.7 Cheese - Removal of the non-edible outer part .6
6.7.8 Cheese - Cutting .6
6.7.9 Cheese - Grinding or blending .6
6.7.10 Cheese - Final preparation steps before analysis or storage .7
6.8 Grinding or blending .7
7 Test report . 8
Bibliography . 9

iii
ISO/DIS 24223:2025(en)
IDF 253:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5,
Milk and milk products, and the International Dairy Federation (IDF), in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 302, Milk and milk products – Methods
of sampling and analysis, in accordance with the Agreement of technical cooperation between ISO and CEN
(Vienna Agreement). It is being published jointly by ISO and IDF.
This second edition cancels and replaces the first edition (ISO 24223 | IDF 253:2021), which has been
technically revised.
The main changes are as follows:
— The scope was expanded from cheese to other milk and milk products.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national interest
groups including dairy farmers, dairy processing industry, dairy suppliers, academics and governments/
food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis and
sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International Standards
using the logos and reference numbers of both organizations.
IDF draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IDF takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, IDF had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. IDF shall not be held responsible for identifying any or all such patent rights.

iv
ISO/DIS 24223:2025(en)
IDF 253:2025(en)
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
This document was prepared by the IDF Standing Committee on Analytical Methods for Composition and
ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being
published jointly by ISO and IDF.
The work was carried out by the IDF/ISO Action Team on C58 of the Standing Committee onAnalytical Methods
for Composition under the aegis of its project leader Mr K. van Cleef (NL).

v
ISO/DIS 24223:2025(en)
DRAFT International Standard
IDF 253:2025(en)
Milk and milk products — Guidance on sample preparation
for physical and chemical testing
1 Scope
This document gives guidance on the sample preparation of milk and milk products for physical and chemical
analysis, including analysis by applying instrumental methods.
This document describes the (sub)sampling, and sample preparation steps carried out after sampling
[1]
according to ISO 707 | IDF 50 and prior to method-specific sample preparations, e.g. as with analytical
methods listed in References [2] to [21].
NOTE Analysis on volatile substances, minor components or allergens can require additional precautionary
measures in sample preparation in order to avoid loss of or contamination with one or more target analytes.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
cheese surface
outer layer or parts of the cheese, even in the sliced, shredded or grated form, including the outside of the
whole cheese, disregarding whether a cheese rind (3.3) has been formed or not
[SOURCE: CODEX STAN 283-1978:2018, Appendix]
3.2
cheese coating
layer or film of non-cheese material which helps protecting the cheese against microorganisms and physical
damage during retail handling and, in some cases, it contributes to the presentation of the cheese
[SOURCE: CODEX STAN 283-1978:2018, Appendix]
3.3
cheese rind
semi-closed layer of cheese with a lower moisture content at the outside of the cheese developed during
ripening of the cheese
[SOURCE: CODEX STAN 283-1978:2018, Appendix]
3.4
non-edible part
part of the cheese that is specified as not intended for human consumption

ISO/DIS 24223:2025(en)
IDF 253:2025(en)
4 Apparatus
The usual laboratory apparatus and, in particular, the following should be used.
The devices and tools to be used should be clean and dry. The devices and tools should not demonstrably
influence the composition of the sample.
4.1 Knife or other suitable cutting device, constructed in a way that pressure on the sample is
minimized to avoid loss of water and water-soluble components.
For samples used for spectrometry or visual analysis, contamination of the cut surface, with cheese rind or
other residuals, should be prevented.
4.2 Peeling device, a razor blade planer has proven to be a suitable device.
4.3 Grinding machine, constructed in a way to produce a small and evenly ground sample portion
without demonstrably influencing the composition of the sample. The device should not produce undue heat.
EXAMPLE An apparatus with a rotating grater, provided with apertures of 1,2 mm to 2,0 mm in diameter, can be
suitable for several types of hard and semi-hard cheese.
The optimal size of aperture can vary with the type of cheese and its maturation level.
4.4 Blending machine (for samples unsuitable for grinding), constructed in a way to produce a small
and evenly blended sample portion without demonstrably influencing the composition of the sample portion.
The device should not produce undue heat.
4.5 Spoons, spatulas or mortar and pestle, of a size matching the required sub-sample size and total
sample size.
4.6 Mixing equipment, optional, any suitable equipment.
4.7 Container with a cover for mixing, of a suitable material, e.g. plastic, and of suitable size.
4.8 Sample containers for storage, of a material and construction, including for closures, that adequately
protect the sample and do not bring about a change in the sample which can affect the results of subsequent
analyses. Appropriate materials include glass, some metallic materials (e.g. stainless steel) and some plastics
(e.g. polypropylene).
The containers should be opaque. If necessary, transparent filled containers should be stored in a dark place.
Sample containers should be securely closed either by using a suitable stopper or a screw cap of metallic or
plastics material.
Containers and closures should be clean and dry. Containers for solid products should be wide-mouthed.
Suitable plastic bags, with appropriate methods of closure, may also be used. If critical for the analysis, light-
excluding containers are advised.
4.9 Sieves for removal of excessive liquids, with an appropriate mesh size.
4.10 Sieves, with nominal size openings of 500 µm, with receiver.
4.11 Water bath, capable of maintaining the desired temperature ±2 °C.
4.12 Oven, capable of being maintained to a maximum temperature of 35 °C.
4.13 Glass beaker, various sizes.

ISO/DIS 24223:2025(en)
IDF 253:2025(en)
5 Sample receipt
In case of receipt of sub-samples from the same product batch, all received samples can be individually
prepared for analysis or be commingled to one sample before sample preparation. The commingled samples
should be properly mixed.
6 Procedure
6.1 General
The procedure as described below should be execu
...