Milling with stones
Milling with stones, which was, until 150 years ago, the only way flour was made, is today a tiny niche in the vast field of flour milling which is dominated by the modern roller mill.
Although an anachronistic niche, its place in the market is assured because enough people are aware that what is special about stoneground flour is that it is truly nutritious. The same could not be said about roller-milled flour which is emaciated, being devoid of the grain’s minerals and vitamins when compared with the stonegound product. Widespread recognition of this state of affairs led to government enacting with Regulations to the Flour Act some seventy years ago that the roller-milled white flour had to be fortified with synthetic vitamins, as well as calcium and iron.
The revival of interest in craft baking has led to a healthy surge in bakers who want to work with stoneground flour. I decided to write about it for this Baker’s Topic after hearing people in the milling trade say that it is “in vogue”. In fact I can truthfully say that both the mills of which I am a customer are unable to keep up with demand and are turning bakery customers away!
The milling process
I shall briefly explain the stone milling process. The stones grind the grain to the class of flour known as “wholemeal”, regarded as 100% of the grain. Then the miller will sieve the wholemeal flour to be able to offer a range of products. The first sieve removes 19-20% of the coarse bran, rendering flour with an Extraction Rate of 80-81%. While this flour is liked by some bakers (I buy a lot of 81% wheat flour from Stoate’s, my landlord mill, to use it as the dark flour for daily feeding of my wheat sourdough and making the Production Leaven before big baking days) generally this first-sieved flour goes to feed the fine sieves to produce so-called “white” flour which is the most popular product and the generator of most income for the miller. The material that cannot pass through the fine sieves is semolina, also a saleable product, but mostly animal feed, while at a few mills it is re-ground to produce more white flour. Regarding the white flour I say “so-called white” because actually it is beige-grey in colour since the stonegrinder’s sieves are not as fine as the industrial miller’s sieves, and the smallest particles of bran are allowed through. With its tiny specks of bran it has both flavour and substance, making a loaf that is slightly greyish in colour, far from white. Its Extraction Rate will be somewhere around 70-72%.
What is most significant about the process is that the stones crush the precious germ at a gently warming temperature, releasing its nutritious oil that spills into the flour. The germ oil contains vitamins B and E (the entire B complex except the important B12), high-quality protein, unsaturated fats, minerals and carbohydrates. Since the flour is suffused with the oil even the most sieved category, the stoneground white, is still highly nutritious. In the industrial roller-milling process the valuable germ is gently rolled flat into a disc that is easily sieved away, and the process does not rupture it, so no oil is spilled. Hence nutrition is sacrificed because the mills do not want rancidity occurring in their products. Rancidity is of course a natural process bound to occur as the oil oxidises and deteriorates. The outcome of rancidity leads the stone miller to date stamp the bags of flour with six to seven months shelf life as the recommended “Best before….” date.
Further nutrition in stoneground flour comes from the inclusion in it of many of the components of the aleurone layer. This sits at the outer edge of the inner (white) endosperm, nestling below the six bran layers. In the aleurone are acids which are powerful anti-oxidants, proteins, and oils and lipids that contain minerals, and water- and fat-soluble vitamins, sterols and lignans. Like the germ, the aleurone layer is indeed a power-house of nutrition.
Working with stoneground flour
Now for the bakerly advice. When you make dough with stoneground white flour you need to be alert to several features of it that are different from roller-milled white flour. Containing its fine bran and more components of the aleurone layer, it has more enzymes. This makes fermentation more brisk, with the contingent risk of over-proof. Further, these natural components lead to an increased stickiness as fermentation is breaking down the starches and proteins, making the dough harder to handle when you are shaping it. Hence it is wise to aim for cooler and slightly stiffer dough, and during the processing, give it shorter rests.
Well, dear Panarians, is it any wonder that, despite being a niche, stoneground flour is here to stay?
Good baking, Paul