The cost of grain that misses specification

A grain handler in northern Europe had agreed to supply a maltster with a contracted volume of malting barley.

When local barley came in with protein above the malting specification, the handler faced an uncomfortable choice. It could reject the material, but the contracted volume would still have to be delivered, most likely by buying replacement barley at a higher price. Or it could sell the barley into a lower-value market and absorb the difference.

Neither option is unusual. Both show that, for a business with supply commitments, the cost of grain that misses specification is rarely just a lower price.

Where the cost falls

Malting barley is bought against a protein window. UK brewing maltsters, for example, normally require 1.60% to 1.75% grain nitrogen, equivalent to 10.0% to 10.9% crude protein (MAGB). Limits differ between maltsters and markets, but the mechanism is similar. Barley outside the range is subject to scaled deductions, with rejection as a last resort (MAGB). Barley that cannot be used for malting usually goes to feed.

For a grower, the loss is the gap between malting and feed prices, and that gap moves. AHDB reported a UK malting premium of £26.30/t over feed barley in late August 2024, against more than £60/t a year earlier (AHDB), and £19.20/t by December 2024 (AHDB).

For a handler or maltster with commitments, the published premium understates the problem. Replacement barley has to be bought, and in seasons when high protein is widespread, barley within specification is scarce. Additional transport and handling follow, as does the risk to the supply relationship.

The usual response is blending: mixing high- and low-protein lots until the average falls within the window. Blending corrects the average, but it uses up good barley and does not narrow the spread. Paul Schwarz, then director of the Institute of Barley and Malt Sciences at North Dakota State University, noted that blending high- and low-protein lots leads to uneven modification in the maltings, and that non-uniform malt is "a larger problem than dealing with a uniform high-protein sample" (NDSU).

What sorting can and cannot change

Single-kernel sorting divides a grain stream into two fractions based on a measurement of each kernel. BoMill InSight, the system the handler installed, uses near-infrared transmission to classify kernels by relative protein-related characteristics. It does not measure the absolute protein content of each kernel, and its sorting criteria are protein-related. Other specification parameters, such as falling number, specific weight, screenings and germination, are not part of those criteria, so each fraction still has to be tested against the full specification rather than assumed to meet it.

For barley with protein too high for malting, separating the higher-protein kernels can leave a lower-protein fraction that may meet the specification. In wheat the logic runs the other way: a lot below a protein requirement may contain higher-protein kernels that can be separated. In both cases, the share recovered and the quality of each fraction depend on the original distribution and the sorting threshold chosen. The handler's aim was to recover part of its out-of-specification barley for malting rather than reject all of it.

"Producing a fraction that meets the specification is a technical result. Whether it is worth doing depends on several further questions"

A suitable fraction is not yet a business case

The comparison that matters depends on who is asking. For a grower, the gain on recovered tonnes is roughly the malting premium. For a handler that would otherwise buy replacement barley, the relevant benchmark is the replacement price, which in a poor season can be well above the published premium. In both cases, the cost of sorting and handling the whole lot, both fractions included, comes off the top, and the result has to hold in an average year, not only a bad one.

The question to investigate

For a processor that regularly receives barley outside its specification, the useful question is not whether sorting works in principle. It is this: in the lots we actually receive, what share could be separated into a fraction that meets our specification, and over several seasons is that share worth more than the cost of separating it, compared with blending or buying replacement grain?

Answering it requires representative samples analysed at kernel level, realistic prices for both fractions, and an honest figure for what the current alternatives cost.

References

1. Maltsters' Association of Great Britain (UK Malt). (n.d.). Barley requirements.

2. Agriculture and Horticulture Development Board (AHDB). (2024, September). Grain Market Daily: Malting premiums sharply lower on the year.

3. Agriculture and Horticulture Development Board (AHDB). (2025, February). Grain Market Daily: What next for the UK malting barley premium?

4. North Dakota State University (NDSU) Agriculture Communication. (2008). Importance of barley plumpness and protein for malt quality.

5. Caporaso, N., Whitworth, M. B., & Fisk, I. D. (2018). Protein content prediction in single wheat kernels using hyperspectral imaging. Food Chemistry, 240, 32–42. https://doi.org/10.1016/j.foodchem.2017.07.048