About this recipe:Sourdough bread comes in many types, depending on the flour used, and this makes a dense rye loaf. In any case it is made with a sourdough starter, rather than packaged yeast, which uses the yeasts that occur naturally in the atmosphere and on flour. It takes time to 'grow' the starter, but then this is not a difficult bread to make, and if you feed your leftover starter you can continue to make more loaves.
For the starter, stir the flour and water together in a bowl to make a sticky paste. Cover with a damp tea-towel (not cling film) and leave on the kitchen counter for 2 days, dampening the tea-towel again as needed to keep it moist. If after 2 days the mixture looks bubbly and has a milky smell, you can proceed to the first feed. (It may take up to 4 days to reach this stage.) If there are patches of mould or the paste smells sour or bad, throw it away and start again with a new batch of starter.
To feed, stir in 100g flour and enough tepid water to make a soft, paste-like dough. Cover the bowl and leave as before for 24 hours. At this point the starter will look very active and bubbly. Stir well, then discard half the starter. Add another 100g flour and enough tepid water to make a dough, as before. Cover again and leave for 12 hours. If the starter looks very bubbly and lively, it is ready to use. If it seems only slightly bubbly, give it one more feed of 100g flour and wait 6 hours.
For the dough, mix the strong white flour and rye flour with the salt in a large bowl and make a well in the centre. Weigh out 200g of the sourdough starter and mix it with the tepid water, then pour it into the well in the flour. Gradually work the flour into the liquid mixture to make a soft dough. You may need to add a little more water if the dough feels dry or crumbly, or more flour if it sticks to your hands or the bowl.
Turn the dough out onto a floured work surface and knead for about 10 minutes or until very pliable. Return it to the cleaned bowl, cover with a damp tea-towel and leave to rise in a warm place for 3 to 8 hours, or until doubled in size. Rising time depends on the room temperature and on the strength of your starter. (A new starter will give a slower rise and less volume than one that is well established.)
Turn out the risen dough onto a floured work surface and knock it back with your knuckles to its original size. Shape the dough into a ball and set it in a basket or colander lined with a heavily floured linen tea-towel. Cover with a damp tea-towel and leave to rise for 2 to 6 hours or until doubled in size.
Towards the end of the rising time, preheat the oven to 220C / Gas 7. Invert the loaf onto a large greased baking tray and quickly slash the top with a sharp knife.
Bake in the preheated oven until the bread sounds hollow when tapped on the base, about 35 minutes.
Transfer the bread to a wire rack and leave to cool. It can be kept for up to 5 days, and is wonderful toasted.
Some more ideas
Leftover sourdough starter can be stored in an airtight container in the fridge. Before using it to make another loaf, bring it back to room temperature, then feed it once as in the main recipe and leave for about 6 hours. Each time you make a loaf, you will have leftover starter. This can be kept in the fridge, feeding it every 4 days to keep it alive, and will improve in flavour. Any starter you do not need or want can be discarded, or given to a friend.