Stoneground flour is a niche product
Stoneground flour, in the vast field of flour milling, is a niche product. Although it is putting the clock back, there is an explanation for why it has not simply died out, and that explanation is found in its inherent nutrition. The stone-grinding process retains an admirable amount of vitamins and minerals, leading to high nutrition when compared with industrial flour which is so refined that it would be fair to call it emaciated, hence the Flour Act makes it mandatory for it to be fortified with synthetic vitamins, iron, and calcium.
It’s more nutritious
Stoneground is nutritious because it is barely refined. While its sieving mechanism may remove about 28% of its bulk as the bran is removed, a beige coloured flour results which still contains fine fragments of bran. Further, it contains significant amounts of the layers between the outer bran and the endosperm (the inner white part). These under-bran layers (particularly the aleurone layer) are highly nutritious, particularly for minerals. Regarding vitamins, not only does it contain the B group of vitamins gained from the endosperm, but more importantly it is suffused with the precious germ oil, that contains three vitamins alone.
Higher levels of enzymes
Along with all this nutrition, stoneground flour has higher levels of the enzymes that lead to brisk fermentation. These are the enzymes that convert starch into the types of sugar that yeast wants to devour. They come with the endosperm, but bigger deposits of them occur around the germ and the under-layers of bran – those layers mentioned earlier that lie between endosperm and outer bran, including the aleurone layer.
Added enzymes mean that the baker must be careful to lower the amount of yeast, and make sure the temperature of the dough is on the cool side. I aim for 22-24 deg C., and I would have yeast at 2% of flour as the upper limit.
The presence of added enzymes and minerals causes the dough to break down more rapidly, and this factor when combined with brisker fermentation activity, leads to the releasing of more water into the dough, which in time becomes softer, and sticky. Hence the baker must be careful to reduce dough water a little and make slightly tighter dough than would occur with industrial flour.
Lower loaf volume
When working with stoneground white, there will not be the same loaf volume as is yielded by industrial white flour. All those tiny fragments of bran will undermine the gluten, even cutting gluten strands, and generally inhibiting the stretchiness of the gluten.
Enhanced signs of ripeness
Finally, the signs of ripeness will be more obvious when the dough is made with stoneground flour. Rather than seeing an array of surface bubbles, at full ripeness the surface of the dough will be more generally deteriorated, looking pock-marked along with surface gas deposits. The baker must be watchful to work the dough before that deterioration is too marked, resulting in the over-proved dough, which will never make the best bread