Sourdough starter

Create your own living sourdough starter from wild yeasts present in the air – this will be a basis of many superb recipes. Good sourdough starts with a good starter. In a week or two you can grow your own – from flour, water and thin air!

Wild yeasts and bacteria exist in the air all around us. These organisms get captured in the flour and water mixture that is exposed to air and over time develop into established colonies, pumping the starter with life and flavour (see Sourdough bread: the process and the science). The starter (sometimes referred to as the ‘mother’) requires little maintenance to propagate and will provide you with leaven for baked goods for a lifetime.

The starter (sometimes referred to as the ‘mother’) requires little maintenance to propagate and will provide you with leaven for baked goods for a lifetime.


Day 0/

100g Organic rye flour
130g Water

Mix rye flour and water in a jar then stand in a cool dark place with the lid on but loose. Here, we are trying to capture wild yeast (to make the bread rise) and lactobacilli (‘good’ bacteria that produce the sour flavour) from the air, so it’s good to allow the mixture to breathe. Organic rye flour is used as the rye contains more wild yeast than ‘normal’ flour, and the lack of treatment with pesticides etc means that these natural beneficial yeasts and bacteria do not get destroyed.

I tend to use warm water – warm to the touch of a finger but not hot. Consistency of the starter should be like that of a thick porridge.

Throughout the development of the starter it’s good to smell the mixture. The smell should never be ‘bad’ – this could be an indication that it has got contaminated and should be discarded. Throughout development, the starter should go through stages where it smells floury, sweet and eventually developing sour notes.

Timings can be variable depending mainly on ambient temperature of the room where the starter is stored.

Day 3/

Bubbles should now be visible in the mixture. At this stage, you may notice a sweet smell.

Remove 65g of starter from the mixture and place in a new, clean jar. To the starter in the new jar, add 65g organic rye flour, 100g water and mix well. Replace lid and keep it loose. Discard the starter in the old jar and clean the jar well – we will use it at the next ‘refresh’. Old starter can be composted.

Suggestion: instead of discarding old starter immediately, I keep it in the fridge until the next refresh. In this way, I always have a backup starter in case something bad happens to the new starter. Like the jar of new starter and two levains for sourdough loaves slide onto a tiled floor and smash into gloopy smithereens. For example.

Day 6/

More bubbles should be visible in the mixture and the height of the starter in the jar approximately doubled from when mixed at Day 3.

As soon as you open the jar, have a smell – you may notice a slight sour smell and an almost effervescent fizzy tingling in the nose – these are good signs of healthy activity.

Remove 30g starter and place in a new clean jar, add 100g organic rye flour, 120g water and mix well.

At this stage I keep the starter in the kitchen and refresh on an ongoing basis as per below if I’ll be using the starter in the next day or so, otherwise it goes into the fridge.

Day 7 and ongoing refreshment/

30g Starter
100g Organic rye flour
120g Water

At this stage, you can switch out the organic rye flour for all purpose white flour, or a mix of white and rye, or stick with 100% rye. If using 100g of all purpose white, I reduce the water content to 100g.

If baking frequently (every day or every few days), the starter can be kept at room temperature and refreshed daily into a new jar with the 30/100/100
ratio (120 water if rye). I tend to bake at weekends only, so I keep the starter in the fridge and pull it out on a Thursday to refresh a couple of times before using to bake over the weekend.