🍎 Determination of moisture content of cereals and cereal products (wheat, rice, barley, millet, rye, oats, triticale, sorghum — grains, milled grains, semolina, flour) by the reference method — a sample of suitable particle size (or ground, with moisture outside 9–15 % after preconditioning) of 5 ± 1 g is dried in an oven at 130–133 °C for 120 ± 5 min (flour 90 min), cooled in a desiccator and weighed; moisture = mass loss in g/100 g, mean of two determinations to 0.01; not for maize or pulses, PN-EN ISO 712-1

Food chemistry PN-EN ISO 712-1

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of ISO 712-1:2024 (English text): title page, contents, foreword and Clauses 1–11 — the sample ends on page 6, before Annex A (results of the interlaboratory test) and Annex B (absolute method). Some headings and parts of sentences are missing in the sample text (e.g. the headings of Clauses 2, 3 and 6, part of the foreword on cooperation with CEN).

ACCORDING TO THE TEXT OF ISO 712-1:2024. The standard was prepared by ISO/TC 34 “Food products”, Subcommittee SC 4 “Cereals and pulses”, in collaboration with CEN/TC 338 “Cereal and cereal products” (Vienna Agreement). The first edition of ISO 712-1 replaces ISO 712:2009 and is a minor revision of it: the numbering and title were changed to align with the new ISO 712-2. Scope (1): a routine reference method for the determination of moisture content of cereals and cereal products — wheat, rice (paddy, husked and milled), barley, millet (Panicum miliaceum), rye, oats, triticale and sorghum in the form of grains, milled grains, semolina or flour; the method does not apply to maize (ISO 6540) or pulses (ISO 24557). There are no normative references. Definition (3.1): moisture content (true moisture content) — loss of mass of the product, in percent. Principle (4): if necessary the sample is ground after conditioning; a test portion is dried at 130–133 °C under conditions giving a result that corresponds to the absolute method of Annex B. Apparatus (5): balance ± 0.001 g; grinding mill of a material that does not absorb moisture, easy to clean, with little dead space, grinding rapidly and uniformly without appreciable heating (temperature difference before and after ≤ 5 °C — cooling helps), airtight, adjustable to the particle size of Table 1; metal or glass dish with lid spreading the test portion so that the mass per unit area does not exceed 0.3 g/cm²; electrical oven maintaining 130–133 °C of air and shelves near the test portions which, set to 131 °C, regains this temperature in less than 30 min after the maximum number of test portions is inserted; ventilation efficiency is checked with durum wheat semolina of particle size up to 1 mm — at full load the results after 2 h and after a further 1 h of drying shall not differ by more than 0.15 g of water per 100 g; desiccator. Sampling (6): not part of the method, recommended procedure in ISO 24333; the sample in an airtight container, undamaged and unchanged. Preparation (7): products with the particle size of Table 1 (100 % passes a 1.7 mm sieve, not more than 10 % remains on a 1.0 mm sieve, at least 50 % passes a 0.5 mm sieve) need no grinding, only mixing; other products are ground — without conditioning when the moisture content is usually 9–15 % (in the laboratory this corresponds to about 20 °C and 40–70 % relative humidity), quickly, an amount larger than the test portion, and the test portion is weighed immediately; with conditioning when the moisture exceeds 15 % (the most frequent case) — the sample (mass m2) is pre-dried as in 8.3 but for 7–10 min and cooled uncovered, outside the desiccator, for at least 2 h (the times may not suit all products, e.g. paddy rice), or when it is below 9 % — left in the laboratory atmosphere until it reaches 9–15 %; after conditioning it is weighed (m3) and ground immediately. Procedure (8): two separate determinations; if the difference exceeds the repeatability limit of Clause 10, repeat until the requirements are met; test portion 5 ± 1 g weighed quickly to 0.001 g into a dried and tared dish; drying of the open dish with its lid in the oven for 120 ± 5 min (flour 90 min) — in some cases, especially in hot and dry countries, the time can be shortened to 60 ± 5 min when this is sufficient to reach constant mass, and the times should be verified regularly; during drying the oven door is not opened and moist products are not inserted before dried ones are removed (partial rehydration); the dish is quickly covered and transferred to the desiccator, dishes are not stacked; weighing after cooling (usually 30–45 min) to 0.001 g. Expression of results (9): without conditioning wH2O = (1 − m1/m0) × 100 g/100 g of product as received; with conditioning wH2O = [1 − (m1/m0)(m3/m2)] × 100; arithmetic mean of two results meeting the repeatability condition, rounded to two decimal places. Precision (10): the interlaboratory test data (Annex A) apply only to moisture contents of 10–18 % and the matrices given there; repeatability limit r = 2.77 × 0.043 = 0.12 and reproducibility limit R = 2.77 × 0.161 4 = 0.45 for moisture contents of 10.00–18.00 %; critical difference of two means of two results within one laboratory ≈ 0.1, between two laboratories ≈ 0.5; uncertainty is derived from the reproducibility standard deviation. Test report (11): sample identification, sampling method (if known), reference to ISO 712-1:2024, results, when repeatability was checked — the final result, details not specified in the standard and incidents, date of test.

STATUS (as of 03.10.2026). In the PKN search (query “712-1”, 03.10.2026) PN-EN ISO 712-1:2025-03 (English version, “Wprowadza: EN ISO 712-1:2024 [IDT], ISO 712-1:2024 [IDT]”) carries no withdrawal note; the other results concern other fields. Card: publication date 03.03.2025, 28 pages, KT 36 Zbóż i Przetworów Zbożowych, ICS 67.060, “Zastępuje PN-EN ISO 712:2012 – wersja polska”, no withdrawal note. In the iTeh catalogue (read 03.10.2026) ISO 712-1:2024 has the status “Published”, stage 60.60 (International Standard published), publication 17.09.2024, with a note that it revises ISO 712:2009.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 03.10.2026). The number 712-1 appears in 4 records at 3 laboratories: AB 103 (2), AB 452, AB 1616. In the current PCA documents (read 03.10.2026; AB 1616 issue no. 13 of 14.10.2025, AB 452 issue no. 25 of 30.10.2025, AB 103 issue no. 42 of 18.02.2026, AB 1275 issue no. 25 of 25.09.2026) the number appears in 5 lines at 4 laboratories — the fourth, AB 1275, still has the previous reference PN-EN ISO 712:2012 in the database copy (the issue of 25.09.2026 is later than the data of the copy). In each of the three documents consistent with the copy the number of page markers equals the number of PDF pages, without repetitions. The form is always “PN-EN ISO 712-1:2025-03”. The lines with the number are not suspended (in the AB 103 document a suspension at the laboratory’s request from 18.02.2026 covers other items, marked in bold italics). The “Laboratories” tab (query “PN-EN ISO 712-1”) shows 3 laboratories — AB 103, AB 452, AB 1616 — checked by a tab query on the labcoda.pl production server on 03.10.2026; AB 1275 still has PN-EN ISO 712:2012 in the database copy used by the tab. The previous edition is still cited in the current PCA documents by three other laboratories (1 record each in the database copy): AB 411 (issue no. 26 of 10.10.2025) — “PN-EN ISO 712:2012”, AB 583 (issue no. 22 of 29.01.2026) — “PN-ISO 712:2012”, AB 1179 (issue no. 21 of 08.07.2026) — “PN-EN ISO 712” without a year; these items are not included in the figures above.

WHAT THE LABORATORIES TEST (items in PCA). Object: cereal grains and cereal products, pasta (AB 103), cereal grains, cereal products (AB 452, AB 1616), wheat grains (AB 1275). Characteristic: moisture content (at AB 1275 “water content (moisture)” and dry matter by calculation). Ranges: (8.3–19.3) % and (10.6–18.0) % (AB 103, two lines), grain (9–20) % and products (9–16) % (AB 452), (10.00–15.00) % (AB 1616), (7.00–20.00) % (AB 1275). Technique: gravimetric method.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Matrix: the standard does not apply to maize and pulses (1), and lists grains, milled grains, semolina and flour as products — pasta (AB 103) is not named in the scope of the standard. Grinding: samples with moisture above 15 % or below 9 % must be conditioned before grinding, otherwise water is lost or gained in the mill (7.2.3); the mill must not heat the sample by more than 5 °C (5.2). Oven: ventilation is checked with durum semolina — the results after 2 h and 3 h shall differ by at most 0.15 g/100 g (5.4); inserting moist portions before removing dry ones rehydrates the latter (8.3). Time: 120 min, and for flour 90 min (8.3). Precision: the limits r = 0.12 and R = 0.45 were determined for moisture contents of 10–18 % (10) — the laboratories’ ranges extend from 7.00 % (AB 1275) to 20 % (AB 452, AB 1275). Result: mean of two determinations to two decimal places, in g/100 g of product as received (9).

WHAT WE DO NOT GIVE. The absolute method of Annex B and the detailed results of the interlaboratory test of Annex A are not quoted — they lie outside the sample. We do not give the numerical value of the uncertainty from Clause 10.6 or the content of ISO 712-2.

Method principle

A sample with the particle size of Table 1 (or ground; with moisture outside 9–15 % — after preconditioning) of 5 ± 1 g is dried in an open dish in an oven at 130–133 °C for 120 ± 5 min (flour 90 min), covered, cooled in a desiccator and weighed. Moisture content is the loss of mass in g/100 g of product as received — corrected for conditioning when it was needed; the result is the mean of two determinations meeting the repeatability condition.

Applications

• Moisture content of wheat, rice, barley, millet, rye, oats, triticale and sorghum — grains, milled grains, semolina and flour (1)
• Not for maize (ISO 6540) or pulses (ISO 24557) (1)
• Cereal grains and cereal products, pasta, wheat grains — items in the accreditation scopes of 4 laboratories in the current PCA documents

Key parameters

Standard

Standard number

PN-EN ISO 712-1:2025-03

Title (PL)

Ziarno zbóż i przetwory zbożowe — Oznaczanie wilgotności — Część 1: Metoda odwoławcza

Title (EN)

Cereals and cereal products — Determination of moisture content — Part 1: Reference method

Step-by-step procedure

1. Sample preparation

   Particle size of Table 1 or grinding; outside 9–15 % moisture — conditioning before grinding (7). PN-EN ISO 712-1:2025-03 with no withdrawal note in PKN (03.10.2026).

2. Weighing the test portion

   5 ± 1 g into a dried, tared dish, to 0.001 g; two test portions (8.1, 8.2).

3. Drying

   130–133 °C, 120 ± 5 min (flour 90 min), door closed (8.3).

4. Cooling and weighing

   Covered dish in the desiccator 30–45 min, weighing ± 0.001 g (8.4).

5. Result

   wH2O = (1 − m1/m0) × 100, with conditioning [1 − (m1/m0)(m3/m2)] × 100; mean of two, two decimal places (9).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Oven at 130–133 °C — hot dishes, heat-resistant gloves
• Grinding grain — dust; airtight mill, wet cleaning

Frequently asked questions