Make your own Sourdough Starter

This is Part 1 of our Sourdough Challenge, our challenge to make your own sourdough starter and bake your first sourdough loaf, written by our baking expert Christopher Robbins. See also Part 2: Sourdough Bread Recipe to learn how to turn your starter into a loaf, and Part 3: Baking Sourdough Bread for Christopher's step-by-step account of his own experience baking sourdough.

Sourdough bread is the most ancient way to make bread. It relies on the natural yeasts and bacteria swirling about in the air to fall onto the mixture of flour and water, which has been left exposed for a few hours before baking. This produced enough ‘leavening’ or rising ‘power’ to aerate the bread dough and produce a lighter, more flavoursome loaf than the rather solid unleavened bread that was the normal product.

This serendipitous discovery some millennia back relied on very small populations of feral yeast dropping into the dough. Rising of the dough was not only extremely slow by modern baking standards, but the slow fermentation (12-24 hours) also changed the composition of the glutens in wheat flours, added new delicious flavours, and gave a more interesting texture to the breads. Modern baking uses a by product of brewing, masses of cheap and concentrated yeast, that produces rapid rising of bread dough (1 hour or less), but this rapid ‘proving’ of the dough does not give the wonderful flavours and textures of slower sourdough proving.

The methods of making sourdough breads are myriad. Some home bakers are terrified of trying to make sourdough, thinking erroneously that it is a complicated process requiring special training and skills. However, it is as easy as making a basic white or wholemeal loaf with baker’s yeast. The only real differences are first, you need to collect and farm some wild yeasts floating around where you live, and second, because you will still have only small amounts of yeast to mix into your dough, the whole mixing and rising or ‘proving’ process necessarily takes a much longer time before you are ready to bake your loaf in the oven.

But when you make your own sourdough, you will be working with natural organisms and primal biological processes, and will have on your table a delicious and responsive bread that will reflect your own techniques and selection of flours. Each loaf will be unique to you and your kitchen.

Here we show my own personal methods. They are not better than others, but are simply the methods that I have found work for me and my kitchen. If you don’t already make sourdough try this method. If you have your own methods or any suggestions to share let us know.

First, we make our starter. Then when it is ready in a week or so, we will show you how to use the starter to make a sourdough loaf.

Sourdough Starter

This is a population of wild yeasts that grow and multiply in a ‘batter’ of strong bread flour and water. The yeasts may be on the wheat berries that were ground into the flour, or have collected from the ambient air when the batter is made and left exposed to the air. You can use white or wholemeal flour. During the next few days, the yeast cells ferment the starches in the flour and multiply happily so long the flour is replenished daily along with some more water. The batter will start bubbling actively and give off beguiling sweet-aromas of fermentation not found in ordinary bread dough. After 5-10days you should have enough starter for a loaf.

Begin by adding about 100g strong bread flour to a large Kilner jar or similar container you can cover. Add enough water, beating gently with a fork, until you have a thick pourable batter the consistency of double cream. Tap water carries contaminants and also pesticides added by the Water Utilities so it’s best to use bottled mineral or spring water if you can. Some people add a few grapes from the garden or some unsprayed apple skin at this stage to increase the wild yeast population, but it is not necessary, nor likely to be of benefit, though should not harm the starter.

Every day add one heaped desert-spoon of strong white flour and an equal volume of room temperature water. Mix this in vigorously with a fork to both mix and add more air. The daily addition of flour ‘feeds’ the multiplying yeasts that are fermenting the starch in the flour. The additional water dilutes the acids formed during fermentation and stops the acidity rising to stop the yeast working. These acids give the sourdough loaf its delicious flavour. You may want to add extra water over the days to keep the batter the same consistency.

You need to have around 500ml starter to make one loaf: enough (300ml) for about 1kg strong bread flour, with enough (200ml) left over to keep feeding for your next loaf. You will achieve your 500ml is a week or so.

Keep the starter in a cool-place, loosely lidded so air can enter, but not any moths, flies, cat’s paws, or dust. It is a mistake to keep your starter in a warm place like an airing cupboard as the warmer it is the more spoiling bacteria are encouraged to grow and they can dominate the less responsive yeasts. The ambient temperature of the kitchen is sufficient. So the rule is “cool is ‘cool’” for both starters and the final proving of sourdoughs.

If, for any reason you cannot feed the starter for 2 or 3 days, feed it and pop it in the fridge, where it will be happy for 4-5 days. The cold temperature will slow down the growth of yeasts, but the starter will not die. When you return, simply remove from the fridge, feed as usual and you are back on track. It is a good idea to split your starter after a few weeks and freeze half, in case of accidents!! (ED: read ‘yeast deaths’ for ‘accidents’). If you have a really successful starter they can be continued for years.

Every starter is unique due to the local population of yeasts. I have two different starters running at present. One created in Gloucestershire and the other came from a friend in Rome. It is called Simone (the starter, not the friend) and it always looks different and makes a different sourdough loaf, even after more than 6 months of feeding and using.

Sometimes your starter may be contaminated or might run out of flour from neglect and it will give up, stopping the happy bubbling and frothing. If it has a layer of brownish liquid on top, pour this off and refresh with flour and water. If this doesn’t revive it or if it has developed a nasty smell instead of the slightly sour, fermentation scents, just discard it and start again. Those who back up their computer diligently are likely also to have a frozen sample they can retrieve and continue with. Otherwise, otherwise.

Get your starter going and keep up. In a week we will show how to turn your beloved starter into sourdough bread.

Christopher Robbins May 2013

See also Part 2: Sourdough Bread Recipe to learn how to turn your starter into a loaf, and Part 3: Baking Sourdough Bread for Christopher's step-by-step account of his own experience baking sourdough.