Nutrient Density

How good are Scotland The Bread’s heritage wheats?

We test every batch of the grain that we grow and the wholemeal flour that we are selling.

Scotland The Bread is breaking new ground by making bread flour available with an analysis of important minerals on every bag. We are concerned to reverse the long-term decline in important nutrients in our daily bread. We believe the best way of doing this is by selecting and growing better varieties of wheat. There is almost certainly no one variety that will combine high levels of all the important minerals, vitamins and phenolic compounds with ideal baking quality and a good yield, every season. So our research is going to take time. The good news is – we can eat the ‘data’, while we examine the subtle interactions of soil and season on minerals, yield and stability.

As we find, select and grow new varieties in many parts of Scotland, we won’t only test them in the laboratory (though this is essential to gradual improvement). We are getingt them out there, as grain, flour and bread to be enjoyed by all. This is research, too. We want people to tell us which varieties they like best and which ‘go down’ best, in the sense of ‘digestibility’ (gut feelings) as well as the whole experience – sharing good bread that comes from a place where everyone is fairly rewarded, and the earth is taken care of into the bargain.

The key to good health increasingly seems to be in the balance that comes with diversity. This is certainly an important feature of healthy soils, sourdoughs and stomachs. So our search for the most nutrient-dense grains that also make good bread and provide a stable yield is likely to lead not to one ‘miracle’ Scottish variety but to highly diverse mixtures, populations and landraces, adapted to their local surroundings, in which a high degree of genetic diversity allows natural resilience, rather than short-term chemistry, to maintain the productivity of food crops that are as good to eat as they can be.

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.

Crop 2019: ‘Balcaskie Landrace’, grown at Balcaskie, Fife.

The average of the Scotland The Bread varieties exceeds the average of four reference values for eight minerals by between 1% and 160% (average 30.4%), with only copper (Cu) being lower (51.7% of ref values).

The high figure for iron in our varieties (especially Golden Drop) needs to be treated with caution as it is so much above the average. It is, however, mostly in line with the other tests (not shown) of the same Scottish varieties grown in other soils and seasons.

Interpretation to follow.

Testing is expensive (roughly £100 per test just for the basic minerals), so our number of samples is small. But we have tested the flour in exactly the same form as we are milling it for sale, so the nutrient levels declared on the bag are at least honest.

The fact that we have had to compare our wheats with an average of four (differing) reference values reflects a degree of official uncertainty in exactly what our bread wheats should have in them. And it may be that the official figures haven’t kept up with the overall decline in nutrient density in modern wheat varieties that has been reported by several studies[1]. One of Scotland The Bread’s aims is to develop minimum standards for wheat micronutrient content in order to challenge plant breeders, farmers and millers to include nutritional quality in their selection criteria. At the moment, high yield (and the rather short-lived disease resistance that shores it up) is the dominant driver of plant breeding and agricultural endeavour, even though this leads to over-production of nutritionally impoverished crops, damage to ecosystems and carbon emissions that simply have to be curtailed. Such a system doesn’t serve ordinary people well, and it leaves farmers on a lonely treadmill, unable to discharge their historic responsibility to feed their fellow citizens well, keep the land in good heart and thereby earn an honest crust.

Despite the caveats and limitations, we can honestly say that our wholemeal flours are, on average, more nutrient-dense than most, if not all, commercial alternatives. We’d be able to make this claim with more confidence if we knew what was actually in other flours, batch by batch and brand by brand. We invite all millers to be as open as we aim to be and, indeed, to join us in working towards higher standards for all flour, for the public good.

The lower-than-average values for copper in our first batch of flours is disappointing. It may be that this mineral is, like selenium, affected more by soil than variety. It is certainly known than wheat is much more sensitive than rye to copper deficiency in soil. We will keep a close eye on levels of this essential mineral in our next crops of wheat which we hope will include some Swedish varieties that have been shown to have above-average levels of copper.

[1] See, for example: Khoshgoftarmanesh, A., R. Schulin, R. Chaney, B. Daneshbakhsh, and M. Afyuni. 2010. Micronutrient-efficient genotypes for crop yield and nutritional quality in sustainable agriculture. A review. Agron. Sust. Development 30:83–107. doi:10.1051/agro/2009017

As funds permit, we want to widen our testing to include vitamins (B and E particularly) and phenolic compounds (e.g. ferulic acid) of which wheat flour can be a good source (provided it is made into bread with extended – ideally sourdough – fermentation).


Support our work

If you would like to support our research and action for better grain and bread, please consider becoming a member of Bread for Good Community Benefit Society and/or donating. The future of good bread is in all our hands.