Mix together 50 ml water (ideally not chlorinated treated) with 50 g of bread flour in a medium size plastic tub.

Cover with the plastic lid and keep somewhere warm (not next to a hot boiler, but comfortably warm - about 23-25C).

You can use gluten-free flours if you want to keep your sourdough bread gluten free.

About 12 hours later, add 100 g water, 100g flour and mix well. Don't discard at this stage

Wait another 12 hours later or little longer (until you see your starter bubbling), discard half of the sourdough starter and then feed again with equal parts flour and water by weight to match the total weight of your starter. (So if you have 70 g starter add 35 ml water and 35 g flour to it for one feeding.)

After another 12 hours, repeat the last step with first taking away half of the sourdough starter and then feeding it.

Carry on for the rest of the week or longer (the longer you leave it the easier your sourdough bread will be to digest), until the starter doubles in volume between feedings.

When your sourdough starter is bubbling and has a well developed slightly sour smell, you are ready to bake!