When I make my bread at home I know as we all do that wholegrain flour is the way to go for health with all its fibre and nutritional qualities. Luckily I like the flavour too so my loaves are rarely made with only white flour. There is more to it than this though: I often hear that stoneground flour is be better for you than roller-milled, but wondered how true this is? At recent conference we were told that only 0.05% of the flour milled in the UK is stoneground. That’s a tiny proportion of the UK four market. We lost many mills over the years, and we love to support small artisan stone ground mills. So, I asked Vanessa about milling our own and about the main differences between the two kinds of flour, nd most importantly how do we get the most from stoneground flour?

This is quite a long newsletter so I will leave my wholemeal loaf recipe until next week. For now, if you fancy it, immerse yourself in the ins and outs of stoneground flour, read on.

Milling your own

You can get some fantastic flavour in your bread by milling your own. It’s also fantastic fun and you kow exactly what is going in your loaf. I have four mills at the Sourdough School.

Komo Mill
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Mock Mill
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Hand mill
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Each one has its pros and cons. I love the rustic finish of the granite hand mill. I feel in touch with the grain and it is an ideal teaching tool for adults and children alike. It’s slow and considered. If you are in a hurry then the beautiful KoMo sitting on the side in the kitchen has its advantages. Flick a switch and you are milling. There is a lovely new little number called the Mockmill that fits the KitchenAid – or any mixer with the accessory drive. Designed by Wolfgang Mock formerly of KoMo, it’s naturally a delight to use and can be put away when not in use. If you have a mixer with a suitable drive then I wouldn’t hesitate to buy it. It’s small, easy to use and mills brilliantly.

Why bother to mill your own?

Flavour, flavour

The Australian Aboriginals repeat the same word to make a point. So a big waterfall I once swam under is called Millaa Millaa Falls. So to make my point, when you think of stoneground flour I’m applying the same principle. Think flavour flavour.

There is nothing quite like the smell of freshly milled grain. It’s like the smell of bailing hay on a summer’s day. It’s fragrant and much like freshly ground roast coffee it has subtleties that are lost as it ages. Stoneground flour contributes significantly to increased flavour in long, slow fermented breads. The higher levels of enzymes accelerate fermentation and so increase levels of volatile organic compounds (lactic and acetic acids). These by-products not only leaven and flavour the dough, but also react with one another to produce compounds such as ethanol. These in turn react together and form esters which give flavour.

A good example of an ester is the result of mixing ethanol and lactic acid to form ethyl lactate, which gives sourdough crumb those wonderful buttery, custardy, fruity flavours. It is these esters, along with various alcohols, aldehydes, and ketones that help to give sourdough bread amazing complex flavours.


Wholemeal flour, whether stoneground or roller-milled contains all of the natural goodness (see the Real Bread Campaign definition for the difference between wholemeal and whole grain).

The fibre and the minerals and the fats from the wheat germ, make moist, nutty moreish loaves. The bran particles in stoneground flour are usually bigger than roller-milled and so the crumb of your loaf will usually be denser and often the result is a moister crumb when baking with stoneground flour.

Stoneground flour differs from roller-milled on several levels mainly because of the differences in process. Stoneground is the result of grinding the cereal between stones until it is becomes flour. Roller-milling is quite different. The roller-milled wholemeal process separates the bran and tears off the outside in a shearing action so this bran is taken away immediately and is sent through to break rollers to make it into a very fine flour compared with stoneground. In the roller-milling process the cereal is broken up into its constituent parts and then recombined to make the flour required. The bran particles in roller-milled are finer and interrupt the gluten network less, so you get a more open crumb structure.

It is important to note that most of the nutrients in wheat are in this outer layer and that the bioavailability of the micronutrients in the grain is hugely increased through the long slow fermentation of the sourdough process (I will cover this in another newsletter later in the year).

The other consideration when comparing the two flour types is that the carbohydrates in stoneground flour are assimilated by the body much more slowly than roller-milled. This is because, as mentioned, the particles of fibre are bigger in stoneground flour which in turn helps to slow down the blood-sugar absorption rate (this is even slower when the bread is naturally fermented using sourdough, and has been shown to slow down further when the flour has been sprouted). Slowing sugar absorption and avoiding peaks in blood sugar is important for our health.

So why is wholegrain better for us?

Long-term it has been shown that a substantial increase in dietary intake of whole-grain high fibre food, in place of more rapidly digested carbohydrates, can improve glycaemic control and so in turn may reduce the incidence of diabetes. Several dietary intervention studies have reported significant improvements in glycaemic control after increasing the dietary intake of whole grain foods, including wholegrain bread; this benefit has been attributed to an increase in soluble fibre intake. It’s really encouraging to know that delicious, moist flavoursome wholemeal flour contains plenty of insoluble fibre associated with a reduced risk of developing type-two diabetes. So making your bread with wholemeal flour means that your bread is both delicious and good for you.

Getting the best results out of freshly milled stoneground flour

When you first mill flour it is “green”…of course it is not actually green, but just means that it has not had time to oxidise. You can make bread with freshly ground “green” flour, but shortly after it is milled, performance drops off until it has had time to age.

The longer version is that the natural ageing of flour by exposure to the atmosphere means that it has had time to oxidise, primarily affecting the sulphur containing amino acids that are constituents of the gluten. The oxidation of two adjacent hydrogen sulphide (thiol) groups (which are mainly located in the aleurone layer) results in the formation of what is called a disulphide bridge between different sections of the long gluten molecule or between different gluten molecules. The formation of gluten involves the creation of disulphide bonds or disulphide bridges. Disulphide bonds are what hold the gluten together. Mixing also results in these bonds being formed and the strengthening of the protein, which is what you need to make good bread.

So the next question is how long does it need to age for?

It is not straightforward as it depends on many factors, such as the way in which the flour is milled, how much oxygen was available to the particles during the milling process, the temperature, the hardness of the grain and the humidity on the day. Many mills add ascorbic acid to the flour, which helps the oxidisation. I know some bakers who refuse to bake with anything less than 8 weeks old. On the other hand, there is something utterly delicious about freshly milled flour. The oxidisation begins to degrade some of the delicate micronutrients.

I have made bread with freshly milled flour many times. It is perfectly possible to bake a beautiful loaf using freshly milled flour but it needs to be very, very fresh. (If anyone can give me a scientific explanation why very fresh flour produces lively dough but within a day it drops away, I’d love to hear it).

So for those of you who are looking to really add nutrition and flavour to your loaves you cannot beat home milling. You will also discover that freshly milled flour is deliciously delicately flavoured, but for maximum gluten development remember to either use it immediately OR age it for a week or so.

We’ve some excellent organic wheat grain from Foster’s Mill.

My final tips on Stoneground Wholemeal

If you don’t want to mill your own then we have some really good wholemeal stoneground flours in stock from Foster’s Mill, Gilchester’s, Redbournbury Mill and Stoates.

Don’t restrict yourself to bread. Use your flour in pastry, cakes, biscuits and muffins.

Blend! It doesn’t have to be all or nothing. Use 20% of your own freshly milled and 80% of your normal flour.

Finally, watch out – the nutrient levels in freshly milled stoneground flour are higher, as are the active enzymes. It will ferment much faster so keep a close eye on your dough or it can run away with you.

Vanessa Kimbell runs the Sourdough School, Northampton


COMPETITION: To win a Komo Fidibus 21 mill with some of Foster’s Mill grain, use Twitter, Instagram or Facebook to send us a photo of your bread with tags #BakeryBits #Komo

We’ll choose a winner at random at the end of the month and announce the results on FB.
(No cash alternative, one entry per person, our selection is final).

featured products

Komo Fidibus 21 Mill | £260.28

The KoMo Fidibus 21 is a small but powerful mill in the KoMo range, beautifully made from beech and with a 12 year warranty and a free supply of grain.

The Priors Organic Wheat Grain | £4.00

This wheat is sold for grinding in a home mill. The wheat has a stored moisture content of around 12%.

Heritage Harvest Heritage Blend Wholemeal Flour | £3.92

A very special flour from Lammas Fayre, this organic heritage wholemeal flour has been produced from over 200 genetically diverse wheat varieties.

Do you have a sourdough question for Vanessa? Send it to us and the best ones will appear in our next postbag edition and receive a dough whisk.

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