Sourdough: leavening and pre-soaking flours

The flours presoaking, left, and the leaven growing yeast, the night before baking of the final loaf.

Last time I explained how to make a genuine sourdough starter, as a pre-cursor to baking a loaf of bread made with conventional flours – wheat and rye – that the gluten-intolerant can safely eat.

As is usually the case, one learns while experimenting, and one such lesson, although as plain as the nose on my face, only struck me a couple of days ago, while visiting a friend for whom I grew a starter from my own.

Whereas I said you must cover the starter bowl with a piece of plastic mosquito mesh, once the microbial action has started and the natural yeasts have begun to work their magic, it makes sense to cover the bowl with a sheet of clingfilm with a small slit in the centre.

This allows the starter to breath, and keeps it moist, but no skin forms on top.

The next step in the process, is the making of a leaven, and the pre-soaking of the flours you’ll use to bake the final loaf.

The leaven replaces the commercial yeast you would normally use, and although it is feasible to include some commercial yeast if your leaven in less than successful, for a gluten-intolerant this is less than desirable. I’ll include it in the recipe as an optional extra.

In the case of all flours, stone-ground is best, because stone grinding does less damage to the components of the wheat seed.

Michael Pollen is adamant that part of the reason modern factory-baked bread is difficult to digest, is the extent to which modern milling depletes the nutritional capacity of the flour.

Ingredients, Selection and Preparation


100g wholemeal wheat flour

100g unbleached wheat flour

200g warm water

75g of your starter


600g wholemeal wheat flour

250g unbleached wheat flour

150g wholemeal rye flour

850g warm water: warm means no more than 25°C, so that you do not kill any of the natural yeast cells in your leaven


The night before you plan to bake, make the leaven and pre-soak the flours.

To make the leaven, combine the wholemeal and unbleached flour in a mixing bowl, and add 75g of your starter. Add the 200g of warm water, and mix thoroughly with a fork.

Cover with a kitchen towel, and leave in a draught-free spot overnight.

Now to pre-soak the flours in preparation for baking the final loaf. This is an unusual step, but I find that it works really well. The idea is that by soaking the flours in water, the process of breaking down the starches into sugars – autolysis – commences long before you begin the proofing process. As important, is the soaking of the bran in the wholemeal flours, which softens it, so that it is less likely to cut to ribbons the gluten which is essential in imparting loft to the final loaf.

There is in fact a constant trade-of between loft on the one hand, and bran content on the other. The more bran in your final flour mix, the less loft you will get in your loaf.

This brings me to another tweak of the recipe, which I only figured out second time round. I sifted the wholemeal wheat and rye flours to remove the bigger pieces of bran, and set them aside after weighing them and replacing the exact weight in unbleached wheat flour. Removing the bran also alters the flavour of the loaf: bran is quite bitter. Keep the bran, because you will use a portion of it just before putting the loaves in the oven.

Combine the wholemeal and unbleached wheat, and wholemeal rye flours in a bowl, with 850g of warm water. Using your hands, blend the mixture thoroughly, making sure there are no dry patches of flour.

Cover with a piece of clingfilm, and set alongside the bowl of leaven, covering both with a kitchen towel.

In case you’re wondering about your new starter, you’ll be deriving it from the leaven you have just made, before you commence the next step in the process: fermenting the flour mix.