About your starter

Your sourdough starter began its life with Cooper's Bakehouse in 2012.  The only ingredients are organic flour and water.  The wild yeasts that enable fermentation arrived naturally in the flour we use and on the air.

Through fermentation, wild yeasts generate carbon dioxide with which bubbles are formed in the gluten of sourdough breads.  The other byproduct of fermentation is organic acid which brings the sour flavour to your bread.

If your starter is not fed, the carbon dioxide and acids it produces will cause it to self destruct.

How to reinvigorate your sourdough starter

To prevent vigorous fermentation in transit, your starter has not been fed for 72 hours plus postage time so revival may take a few days.

First find a clean container with a loose fitting lid.  A vigorous starter will generate enough carbon dioxide to crack a sealed glass container so be careful.

Keep your starter at room temperature whilst you're attempting reanimation.

day 1: add the contents of your sourdough vial to 20g water and 20g organic bread flour

day2: add 20g water and 20g flour

day 3: add 40g water and 40g flour

day 4: add 80g water and 80g flour

By this point you should see evidence of fermentation taking place with bubbles forming.

Carry on matching the quantity of flour and water already in your container until fermentation is seen.  If you run out of container space pour some starter away so that you can match the existing quantity.  

You must always match or exceed your quantity of sourdough starter to prevent the acids building up to a point where they kill the yeasts.  For example if you have 100g of starter you must add 50g water and 50g flour as a minimum to prevent acid buildup. 

If your recipe calls for more starter and your culture is vigorous, you can add more flour and water in equal measure.   At Cooper's Bakehouse we regularly multiply our starter by over ten times in a single day.  On the few occasions when we have underfed our starter we have accidentally sent it to sleep.

Keeping your starter

In large quantities (over 1kg) your regularly fed starter will stay active in the fridge.  In a jam-jar sized container it will probably stop fermenting in the fridge and come back to vigorous life when fed (with flour and water) and returned to room temperature.  

If you store your starter in the freezer it may become dormant beyond recovery so if you're experimenting, don't freeze it all.

The rule of thumb for keeping your starter is that if it's fermenting vigorously it will need feeding regularly and at the other end of the spectrum if it looks inactive it either needs feeding or returning to room temperature.

The more regularly you bake, the more you will use and feed your starter and the happier it will be.  You'll also become better and judging how active your starter is and how it likes to be cared for.

Baking with your starter

The techniques for baking sourdough are beyond the scope of this page but the following quantities work well for Cooper's Pain de Campagne.

We build our starter into a production levain which we keep in the fridge for 24 hours before we mix it to form the final dough which spends a further 24 hours in the fridge before its final proof at room temperature.

production levain

starter 100

wholemeal 30

strong white 100

water 78


production levain 308 (as above)

wholemeal 100

strong white 310

water 300

salt 10

For more advice please do get in touch with Cooper's Bakehouse or sign up for one of our baking courses.

Good luck.  Happy baking.