Milling wheat crops harvested this summer are showing average grain protein levels below breadmakers’ minimum standards, due largely to the very dry spring and summer, while specific weight and Hagberg levels look high.

The average protein of Group 1 milling wheat varieties across Britain is 12.5% for the 2022 harvest, below the normal breadmaking standard of 13%, and this is down on the 2021 harvest at 13.2% and the three-year average of 13%, according to the AHDB’s Cereal Quality Survey, using data up to 30 August.

The low wheat protein contents are likely to be due to limited nitrogen fertiliser uptake by milling wheat crops reflecting the hot and dry weather and therefore lack of rain to wash the nitrogen into the soil, and also some grain protein dilution from the high wheat yields being reported.

See also: Harvest 2022: The 5 top-yielding winter wheat varieties map

Average Group 1 wheat Hagberg levels – a measure of wheat gluten quality – was 346, well above 2021 and the three-year average levels, while the average specific weight was 81.8kg/hl, up 6.4kg/hl on 2021 and 4.2kg/hl ahead of the three-year average.

Overall, 31% of Group 1 wheat samples were meeting a typical breadmaking standard of 13% protein, 250 Hagberg and 76kg/hl specific weight, up from 20% in 2021, while 73% of Group 1 samples met a lower specification of 12% protein, 200 Hagberg and 74kg/hl specific weight.

Malting barley

Over on the barley side, the average nitrogen contents for malting varieties in Britain was 1.52%, the second highest since 2017, compared with 1.49% in 2021, with the highest nitrogen levels in the eastern region of England at 1.62%, while the lowest were in Scotland at 1.41%.

The Maltsters’ Association of Great Britain says nitrogen contents of 1.6-1.75% are generally required for brewing, while for distillers 1.5% is considered optimum, but they will use grain up to 1.65% nitrogen.

Scottish crops are aimed at the distilling market, so tend to show lower nitrogen levels than English crops.

Winter barley nitrogen levels averaged 1.62%, up from 1.57% in 2021, while spring barley averaged 1.49%, again up slightly from last year at 1.48%.

Specific weights were also higher, with an overall average for winter and  spring crops at 67.3kg/hl, up on 2021 and the three-year average.