How many teaspoons of sugar in barley bread?

Of the seven loaves on Dr Unwin’s bread chart, the wholegrain barley bread has the highest glycaemic index, at 85, and the largest glycaemic load, at 15. The chart describes it as 50% barley and does not say what the other half of the flour is.

Barley as a grain is often cited in GI research for low values, particularly pearl barley and whole kernels cooked in water. This row describes a different product. Once barley is milled into flour and baked into a loaf, its starch is swollen by heat and water and finely divided, and the reputation of the whole grain does not carry over automatically. The chart does not say how coarsely the barley was milled, and GI tables list barley breads made in different ways with very different values.

Both the load and the teaspoon figure are printed on the chart rather than calculated here. The portion, as on every row of the chart, is one small 30g slice.

A GI value is an average from a small group of volunteers, often around ten, and one tested recipe stands in for a whole kind of bread. A loaf labelled barley bread in another shop may be made quite differently.

Among the seven breads on the chart, the teaspoon figures run from the stoneground wholemeal slice at the low end to this loaf at the high end. All seven are set out in a table in why brown bread is still sugar.