Don’t be scared of making a leaven for your sourdough. It’s not hard, and will take about five days: which is tedious if you want to start making bread today. However you could ask a friend – lots of people make sourdough nowadays and they might have a bit of ‘mother’ they can let you have. The difference between leaven and the dried or fresh yeast you can buy in a shop is that the sourdough leaven is made using live yeast which are in the the world around us. In that way it has a sense of the magical. Its also what our ancestors used to make bread, so there is a great sense of history in sourdough.
Ingredients. Your will need an organic potato and some rye flour, and a container, preferably glass.
Storing the starter. You can measure the starter in a marked container, then transfer to your glass jar - this is good practice as you glass jar should be clean. Wash it every time you take the starter out to revive it, once you have removed the starter. Never put the lid on tight when you store the starter, keep it loose.
Flour. If you can't get rye flour use strong bakers flour, white, preferably not wholemeal. I use rye flour because of all the starter flours it is the most forgiving if you neglect it! I had a rye flour starter in the back of the fridge for a year and I still managed to revive it after feeding it for a couple of days. It also adds an additional bit of flavour to your bread. Wholemeal flour I have heard, tends to 'cut up' the gluten, so is not the best flour to use for a starter. Try strong white bread flour if you can't get rye.
Day 1: Get an organic potato, wash it and clean it and peel it. Put a piece of the peel into a clean glass jar and add a tablespoon of rye flour and a tablespoon of tepid water, and mix together. Cover with a muslin cloth or open weave tea towel.
Day 2: Uncover jar and add another tablespoon of water and of flour and mix well with the rest. Cover and leave in a warm place.
Day 3: You should notice some bubbles beginning to form and a pleasant yeasty smell, and possibly a slightly acidic smell. Add another tablespoon of flour and of water and stir.
Day 4: Fermentation should be happening by now. Add another tablespoon of flour and tepid water and mix, and remove the potato peel.
Day 5: Your leaven should almost be ready. It should be nice and bubbly and smell sweet and tangy. Add another tablespoon of water and flour and stir.
Day 6:You should have a proper leaven by now. Leave it in a warm place and then weight it. Add equal amounts of water and flour to match the weight of the leaven. ( If you have 150 gms of leaven , add 75 gms each of water and flour. This is called 100% hydration.)
The leaven pictured had been out of the fridge overnight and I then added flour about an hour before I took the photo. It will develop more bubbles as it feeds on the flour.
Use whatever you need for baking, keep some and discard the rest. If you keep it in the fridge you will need to feed it once a week, as above. You can use the discard to make crumpets.