My starter seems to be pretty lively, and you might need to increase some of the times here for a less active one.
I use the following equipment and ingredients, but there are alternatives for most of the equipment (much of which wasn't available a few centuries ago, but people still managed to bake bread):
- Oven (mine is fan assisted and efficient, so if yours runs cool you probably want to add 20°C to the temperatures.)
- Electric kettle
- Kenwood mixer with dough hook (or knead by hand. A lot.)
- Pizza stone
- Big baking tin
- Small plastic tub with lid
- Large bowl
- Baking parchment
- Lame (a sharp blade for slashing bread before it goes in the oven. You can try using a serrated bread knife instead.)
- Pizza peel (a flat board on a stick for lifting bread-based products in and out of the oven.)
- Two flat baking sheets
- Spray bottle of water
- Wire cooling rack
- Two plastic dough scrapers
- Spray-on olive oil
- White flour (as strong as possible; use "extra-strong" or whatever you can get. The best I've found easily available in the UK is Waitrose extra strong Canadian flour, with 15g of protein per 100g. If you use regular bread flour, with around 12.5g of protein per 100g, your loaves will collapse in the fridge)
- Water (Some people recommend using bottled water to keep your starter alive; I've not had any problems with London tap water (which is treated with chloramine))
- Sourdough starter (kept in the fridge from last time. If you didn't have a last time, try mixing 150g of flour and 150ml of water, keep it covered (but not airtight) at room temperature, and every day throw away half of it and add another 75g of flour and 75ml of water. Keep doing so for 2-4 weeks, and with any luck you'll have a reasonable starter, although it will get better with time. Or find someone who already has a starter)
To make four loaves of around 400g each:
Four days before you want to eat the bread, take your starter (should be 200g to 250g), put it in the large bowl and increase it to 700 to 750g by adding equal weights of flour and water. Leave overnight.
Next day, it should be a frothy mass. Pour off 450g into the mixer bowl, and put the rest in the small plastic tub. (Leave it in the fridge for the next time you bake bread. It will need feeding every couple of weeks if you keep it in the fridge.) Add 300g of flour and mix lightly using the dough hook -- a minute should do, as you're not actually kneading it at this point, just making it a homogenous lump. Cover the bowl with clingfilm, leave it to rise for two or three hours, and when it's doubled in volume, put it in the fridge overnight.
Next day, leave it out for an hour to warm up to room temperature. Break the lump up into small pieces. Add 500g of flour and 500ml of water and mix lightly with the dough hook (another minute or so). Cover it with clingfilm again and leave for 30 minutes to autolyse. Now start properly kneading it in the mixer, for seven minutes. Add a tablespoon of salt, then slowly add in another 175g of flour while it mixes. Re-cover with clingfilm and leave it to rise for a couple of hours or so, until doubled in volume.
Put a sheet of baking parchment on each of your baking sheets. Flour a work surface and tip the dough out onto it. Use the scrapers to divide it in half, then divide each half into half again. Take each piece and shape it into a flattened sphere, folding it back on itself to get good "surface tension". When each one is done, but it on the baking parchment on a baking sheet, two per sheet. Spray them with oil, cover them with clingfilm and put them in the fridge to rise for two days.
Two days later, they should be well risen. Take them out of the fridge for an hour to warm up to room temperature. Meanwhile, put the large baking tin on the oven floor and put the pizza stone on a low shelf (but not so low that you can't get at the baking tin). Pre-heat the oven to 230°C, and leave it there for at least 15 minutes to let the stone heat up.
Boil some water in the kettle. Remove the film from one baking sheet and slash the loaves a couple of times, then a couple more at 90° to the first slashes. Use the pizza peel to lift the baking parchment (with the bread on it) off the baking sheet and put it on the pizza stone on the oven shelf, pour half a mug of hot water into the baking tin, spray water from the spray onto the sides of the oven (not onto the lightbulb, and not too much onto the bread), and close the oven. After five minutes, reduce the temperature to 200°C and spray some more water onto the oven sides. After 25 minutes, the loaves are done. Take them out and cool them on a wire rack. Reheat the oven to 230°C and do the other two loaves in the same way.
They freeze very well. To reheat, put them in a cold oven, turn it on to 200°C and leave for 20 minutes (or longer if your oven heats up slowly; mine gets to 200°C from cold in about 8 minutes).