Your starter may have bubbled a little but now it just looks flat and a layer of unsavoury-looking liquid is beginning to appear on the surface. You don’t see how this is going to raise your bread if you use it. Or perhaps you’ve made a loaf with it and it didn’t rise much.

What to do

The following steps (which can be repeated if necessary) will dilute excessive acidity and provide nutrients for the yeasts in your starter:

  1. Take just 10 grams (or a flat teaspoon) of your starter and put it in a fairly small glass, ceramic or plastic bowl or jar.
  2. Add 30 grams of rye flour (wholemeal if possible, because the branny bits are much richer in wild yeasts and bacteria than the white flour) and 60 grams of warm water (at about 40°C). Warmth is really important to the development of both the yeasts and the bacteria that occur naturally in the starter and the flour.
  3. Mix this all up with your fingers. Your hands have important beneficial bacteria on them and, provided you observe normal personal hygiene measures, you will probably add useful elements into the sourdough just by mixing by hand. The bacterium Lactobacillus sanfranciscensis, the organism at the heart of the famous San Francisco sourdough bread, is, unlike most sourdough bacteria, not found in flour and is presumed to get into sourdough on the hands of bakers.
  4. Cover and leave in a warm place (but not over 35°C and not in direct contact with e.g. a radiator) for 16-20 hours. It should be beginning to bubble a little at this point. If it is, you can proceed to use it to make a ‘production sourdough’, as described in the recipe that accompanied the starter.
  5.  If nothing is happening, it may be that the acid-forming bacteria are over-active and are getting away before the yeasts can show signs of working. The remedy for this is to repeat stages 1-4. This will dilute any accumulated acidity again and should provide a neutral platform for the yeasts to grow normally.