EN 15587 Besatz in Wheat: Complete Technical & Operational Guide

What EN 15587:2018 Defines

In the European grain trade, determining the physical purity of a bulk delivery is as critical as measuring its protein or moisture content. EN 15587:2018 (Cereals - Determination of Besatz in wheat (Triticum aestivum L.), durum wheat (Triticum durum Desf.), rye (Secale cereale L.), triticale (xTriticosecale Wittm. ex A. Camus) and feed barley (Hordeum vulgare L.)) is the definitive European standard governing this physical inspection.

The German term Besatz translates to “admixture” or “impurities.” In the context of EN 15587, it encompasses all material within a 100g sample that is not the flawless, unimpaired basic cereal grain being traded.

The standard exists to unify testing methodologies across European laboratories, removing the ambiguity that historically plagued cross-border grain contracts. By establishing rigid definitions for what constitutes a “broken grain” versus a “shrivelled grain” versus “Schwarzbesatz,” EN 15587 ensures that a milling cooperative in Germany and a port terminal in Poland assess physical intake quality using an identical analytical language.

It is important to note the scope: EN 15587 covers common wheat, durum, rye, triticale, and feed barley. It does not cover oats, maize, or malting barley (which relies on EN 16378). Furthermore, the standard strictly dictates physical and visual properties. Chemical parameters—such as protein, moisture, falling number, or specific weight—fall completely outside the purview of EN 15587.

Besatz Fraction Breakdown

The foundation of EN 15587 is the systematic separation of a raw sample into highly specific fractions. The unblemished kernels are considered the “basic grain,” while everything else is separated into four primary Besatz fractions.

Broken grains

A grain is classified as broken if a portion of the kernel is missing, exposing the endosperm. The strict visual rule in EN 15587 requires that the endosperm is clearly visible to the naked eye. If a grain is merely scraped or possesses minor surface mechanical damage without exposing the internal starchy matrix, it remains basic grain.

In wheat, grains where only the brush (the hairy end) is missing, or where the germ is dislodged without exposing the endosperm, are generally not penalised as broken grains. The precise separation of broken grains is critical because high broken percentages drastically reduce milling yields and increase susceptibility to pest infestation and mould during silo storage.

Grain impurities

This fraction is often the most heavily debated during intake, as it relies on subjective visual thresholds and precise sieving. It includes:

• Shrivelled grains: Grains that are under-developed, lightweight, and thin. For common wheat, the standard procedure typically utilises a 1.8 mm slotted sieve. If the grain passes through this sieve, it is classed as shrivelled. For durum wheat, a 1.9 mm sieve is often applied.
• Other cereals: Any cereal species not matching the primary bulk. For instance, kernels of rye or barley found within a common wheat delivery.
• Pest-damaged grains: Grains showing visible boring, nibbling, or internal excavation by insects (such as the grain weevil Sitophilus granarius).
• Grains with discoloured germs: Wheat kernels where the germ is visibly discoloured (typically dark brown to black), often resulting from oxidative stress or specific microbial activity.
• Heat-damaged grains: Grains that exhibit a distinct brown to black discolouration externally, and when cut open, present a yellowish-grey to brownish-black endosperm. This damage usually stems from aggressive artificial drying at excessive temperatures or spontaneous heating due to high-moisture storage.

Sprouted grains

Sprouting is a catastrophic defect for milling wheat, intrinsically linked to high alpha-amylase activity and low Hagberg Falling Numbers. Under EN 15587, the assessment of sprouted grains is strictly visual.

A grain is classified as sprouted if the radicle (rootlet) or plumule (shoot) is clearly visible. Crucially, if the seed coat over the germ is merely swollen, split, or ruptured—but no sprout is protruding—the standard dictates it is not a sprouted grain. This visual distinction requires sharp laboratory focus, as a 0.5% shift in sprouted grain count can mean the difference between milling grade and feed grade.

Schwarzbesatz

Translating directly to “black impurities,” Schwarzbesatz represents the most severely penalised category of defects. These are the miscellaneous, often hazardous, impurities that must be ruthlessly extracted prior to processing.

• Weed seeds: This includes both non-toxic seeds and highly regulated toxic seeds (e.g., Datura stramonium).
• Ergot sclerotia: The dark, horn-shaped fungal bodies produced by Claviceps purpurea. Because ergot contains highly toxic alkaloids, its presence is strictly controlled.
• Extraneous matter: Inorganic materials such as stones, sand, mud balls, and dust, alongside non-grain organic matter like straw, chaff, and plant stems.
• Impurities of animal origin: Dead insects, insect fragments, rodent hairs, and pest excreta.
• Fine impurities: Any miscellaneous dust or fragments that pass through the initial 1.0 mm slotted sieve prior to manual sorting.

EN 15587 Sampling and Sub-Sampling Procedure

To achieve repeatable results, the physical methodology applied at the lab bench must be as rigorous as the definitions themselves. The process relies heavily on initial compliance with EN ISO 24333 (the standard for cereal sampling). The laboratory typically receives a 250 g to 1 kg submitted sample; for Besatz determination specifically, a 100 g working portion is then extracted using the sample divider before sieving begins.

1. Composite Preparation: A representative bulk sample is drawn from the lorry or railcar using automated probing systems. This bulk must be thoroughly homogenised.
2. Sub-Sampling: Using a validated mechanical sample divider (such as a riffle divider or rotary divider), the analyst extracts an exact sub-sample. For wheat, durum, rye, and triticale, this sub-sample mass is approximately 100g. For feed barley, a 100g working sample is used.
3. Initial Sieving (1.0 mm): The 100g sample is weighed to an accuracy of 0.01g. It is then passed over a 1.0 mm slotted sieve (or agitated in a mechanical sieve shaker). Every particle that falls through this sieve is immediately weighed and logged as Schwarzbesatz.
4. Manual Separation: The material retained on the sieve is spread onto a clean, contrasting surface. Operating under bright, diffused laboratory lighting (ideally 5400K daylight bulbs), the analyst uses tweezers and a magnifying spatula to manually segregate every single kernel into its respective EN 15587 fraction.
5. Weighing and Calculation: Once fully segregated, each fraction (broken, grain impurities, sprouted, Schwarzbesatz) is individually weighed to 0.01g precision. The mass is then expressed as a percentage of the total initial sub-sample weight.

Typical Limits in EU Trade

Compliance with EN 15587 is not merely a laboratory exercise; it directly dictates the financial value of the crop. European Regulation (EU) No 1308/2013 and various national and commercial quality schemas enforce strict maximum thresholds for these fractions.

While individual milling contracts vary, the following table illustrates the typical maximum Besatz limits encountered in standard European trade for common wheat and durum:

Cereal Category	Total Besatz (Max %)	Broken Grains (Max %)	Sprouted Grains (Max %)	Schwarzbesatz (Max %)
Common Wheat (High-Grade Milling)	5.0%	2.0%	1.0%	1.0%
Common Wheat (Standard Milling)	7.0%	4.0%	2.5%	1.5%
Durum Wheat (Pasta Grade)	5.0%	3.0%	1.0%	1.0%
Feed Wheat	10.0%	5.0%	No strict limit	3.0%

Within the 1.0% Schwarzbesatz limit for milling wheat, sub-limits are severely enforced. Ergot sclerotia, for instance, is typically capped at 0.02% (200 mg/kg) under EU food safety regulations, while certain toxic weed seeds operate on a near-zero tolerance basis.

Manual Besatz Determination: Why It’s the Lab’s Biggest Bottleneck

Despite the standard’s precision, the operational reality of executing EN 15587 in a busy grain intake laboratory is highly problematic. The manual separation of a 100g sample requires an analyst to visually inspect between 2,500 and 2,800 individual kernels.

Under optimal conditions, an experienced laboratory technician requires 20 to 30 minutes of dedicated bench time to process a single wheat sample accurately. During the peak harvest season, when a commercial mill or cooperative might receive 40 to 60 truckloads per shift, the mathematical bottleneck is severe. Forty trucks at 25 minutes each equates to over 16 hours of purely manual physical sorting.

This sheer volume of manual labour leads to two critical operational failures:

First, intake delays. Lorries stack up in the yard waiting for laboratory clearance. If the lab rushes the Besatz analysis to clear the backlog, they inevitably miss subtle defects like heat-damaged grains or minor pest boring.

Second, analyst fatigue. Staring at 2,800 kernels under bright light causes significant eye strain and cognitive fatigue. In practice, laboratory supervisors report that error rates in visual fraction categorisation climb noticeably across a long shift, particularly in the final hours of a busy harvest day. When an analyst is fatigued, a grain with a split seed coat might accidentally be thrown into the “sprouted” pile, or a piece of triticale might be missed entirely among the wheat kernels.

To understand the scale of this operational challenge, reviewing how AI compares to 5 lab technicians provides a clear view into the variance introduced by human fatigue in standardised methodologies.

Common Mistakes and Disputes

The subjectivity inherent in manual human inspection frequently leads to disputes between the seller (farmer or cooperative) and the buyer (mill or port terminal). Common edge-case disputes under EN 15587 include:

Heat-Damaged vs. Natural Variation: Natural environmental stressors or specific varietal traits can cause minor darkening of the kernel. Distinguishing this natural colour variation from genuine heat-damage (which compromises gluten integrity) is notoriously difficult. If a lab incorrectly penalises a shipment for heat-damage, the financial downgrade is severe.

Fusarium-Damaged Kernels (FDK): The standard groups various visually shrunken, chalky, or pink-discoloured grains into grain impurities. However, determining the exact visual threshold at which a kernel is definitively “Fusarium-damaged” rather than just lightly shrivelled requires extensive training. Proper classification here is vital due to the mycotoxin risk associated with fusarium in European grains.

Ergot Sclerotia Fragments: Ergot bodies are highly brittle and often shatter during transport or auger handling. Analysts must meticulously hunt for tiny purple-black fragments, often only a few millimetres across and easily confused with charred plant debris. Missing these fragments not only violates the Schwarzbesatz limit but directly breaches ergot alkaloid limits in food safety law.

“Other Cereals” Identification: Separating rye from wheat is generally straightforward. However, identifying modern triticale varieties (a hybrid of wheat and rye) within a common wheat sample tests the limits of manual visual inspection. Triticale kernels often closely mimic large wheat kernels, leading to frequent misclassification and subsequent disputes over grain admixture standards between EU and US markets.

How Automated Visual Inspection Supports EN 15587

To resolve the intake bottleneck, modern European laboratories are adopting automated visual inspection technology alongside their existing chemical analytical equipment.

It is vital to understand the technological division of labour at intake. Standard laboratory equipment from manufacturers like FOSS (Infratec), Perten, or Bruker utilise Near-Infrared (NIR) technology to measure chemical properties: moisture, protein, starch, and fat. However, NIR cannot perform physical EN 15587 Besatz analysis. It cannot see a broken grain, a weed seed, or a sprouted radicle.

This is where automated optical systems like GrainODM complete the quality control workflow. While the NIR analyser is running its 60-second chemical scan, a parallel 100g sample is fed into the visual analyser. Using computer vision and AI models trained on millions of annotated kernels, GrainODM individually inspects and classifies every kernel according to EN 15587 fraction categories.

The optical system identifies broken grains, shrivelled grains, other cereals, and Schwarzbesatz components like weed seeds and ergot. It performs the 30-minute manual sorting task objectively in seconds, documenting the exact percentages and providing photographic evidence of the defects. By working alongside the NIR equipment, visual automation completely digitises the intake workflow, ensuring compliance with physical standards without succumbing to analyst fatigue.

EN 15587 and Cross-Border Trade: GAFTA, FOSFA, EU Intervention

Standardisation is the bedrock of international grain trading. The strict definitions within EN 15587 are deeply embedded in wider European and global trade frameworks.

When executing contracts under the Grain and Feed Trade Association (GAFTA), particularly GAFTA 124 (Sampling Rules), the physical determination of impurities at European discharge ports defaults to EN 15587 methodologies. A vessel arriving in Rotterdam or Hamburg from the Baltic states will be sampled according to ISO 24333, and the Besatz will be quantified precisely to EN 15587 fractions to determine if the cargo meets the contractual specifications.

Similarly, the European Union’s intervention buying programme relies on this standard. When market prices fall and national agencies purchase surplus wheat to stabilise the market, the intake quality criteria are uncompromising. Intervention silos require detailed laboratory certificates proving that the total Besatz, broken grains, and Schwarzbesatz fall strictly within the limits set out in EU Regulation 1308/2013, ensuring that long-term strategic stores maintain optimal grain purity test standards.

Moving from Manual to Validated Besatz Workflow

Operating a modern, high-throughput grain intake facility requires shifting away from subjective, 30-minute manual bench separations. Digitising the EN 15587 physical inspection removes your most critical harvest bottleneck, ensures absolute consistency between shifts, and permanently eliminates supplier disputes over defect categorisation. By deploying automated visual analysis alongside your existing NIR chemical instrumentation, your laboratory can achieve a complete, compliant, and instant quality profile. To evaluate how computer vision can standardise your Besatz determination this harvest, schedule a technical demonstration with our team.

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Reference standards and regulations cited in this guide:

• EN 15587:2018 — Cereal and cereal products — Determination of Besatz in wheat, durum wheat, rye, triticale and feed barley (CEN)
• Regulation (EU) No 1308/2013 — establishing a common organisation of the markets in agricultural products (EUR-Lex)
• GAFTA Sampling Rules No. 124 (Grain and Feed Trade Association)