We test the grain as it comes from the field and then samples of wholemeal flour produced on Scotland The Bread’s cyclone mill. This contains all of the wheat grain, finely ground without being heated up. The tests for key minerals are performed by the James Hutton Institute, one of Scotland’s leading science institutions. The results are shown in the tables here.
To establish whether our wheats are more or less nutrient-dense than average, we consulted four sources of ‘reference values’: McCance & Widdowson, the UK ‘bible’ of food composition, an academic paper that set benchmarks for a range of micronutrients in organic cereals, and the national nutritional reference tables from Denmark and Sweden. We have measured our wheats against an average of these reference values.
We didn’t include reference values from the US Department of Agriculture because the climate and soils in the main wheat-growing areas of the USA are significantly different from the UK’s. North American soils are usually much richer in selenium (an important mineral) than UK soils and the amount of selenium in wheat is influenced more by soil than variety. So even high-mineral varieties grown in Scotland are likely to compare unfavourably with standard values based on selenium analyses of wheat grown in the USA. Our search has to be for varieties that make the most of the modest amounts of selenium in most Scottish soils.