Sourdough leaven

Before the widespread use of commercial bakers yeast, leaven was used was used to make bread rise. Alan Reid takes us through this traditional preparation method
Sourdough leaven
  • Rating:
  • Effort: easy


  • organic potatoes
  • whole rye flour
  • water

Tips and Suggestions

get used to the smell of your leaven it should be sweet and pungent, smelling of apple cider when very ripe.

Feed your leaven at the same time every day so that you dont forget it (last thing at night is best) and dont expose it to direct sunlight.


1. Wash and peel organic potatoes - potato peelings are rich in lactose bacteria and yeast (sourdough culture).

2. Submerge the peel in a cup of cool water, add 2 tablespoons of whole rye flour and mix. Store in a glass, ceramic or plastic container with a loose-fitting lid (to prevent contamination from other organisms). Keep this mixture in a room that stays at a constant temperature (a pantry for example). Bubbles should form in mixture after two or three days.

3. Remove the peel and mix in more whole rye flour to make slurry. Use approximately 3 parts water to 2 parts flour. If your mixture is too thick, the yeast and bacteria wont migrate easily; if it is too thin, their food will run out too quickly.

4. For the next week dispose of all but one tablespoon of the mixture each day. Mix this tablespoon through a fresh batch of flour and water. This is called feeding your leaven.

5. After one week, start disposing of all but one teaspoon of the mixture each day. Your culture should take 12-24 hours to reach peak activity. Bacteria and mould will take over if too much ripe mixture is transferred into the fresh batch or if the ripe mixture is left for too long. Allow one more week of daily feeding whilst the mixture or leaven matures.

6. The night before baking, add one teaspoon of ripe leaven to a fresh batch of flour and water. It should be ready to incorporate into your dough in the morning.

Ready to make bread? Try our plain sourdough recipe

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