Put raisins or fruits in a glass bottle. Add water until fruits are soaked. Crush or cut fruits. Add sugar or honey if fruits are not sweet enough.
Let it sit at room temperature.
Check bubbles of gas coming to the surface.
Starter-liquid is completed in 1 to 7 days in some environments.
Mix starter-liquid and flour. Put it in room temperature.After 6-12 h, the mixture should have gone bubbly and doubled up.
Add water, flour, salt to step3's product, and knead the dough well. Put it in a bowl or plastic container with lid and let tripled all night long (12-15hr, or more, at 15 degrees C (59 degrees F), 5-8hr at 20-25 degrees C(68-77 degrees F)). Shape the loaf, wait about 2hours for secound rise, and bake it.
Add honey&water,fruit&water,or fruit juice to this starter-liquid. Let it sit at room temperature for hours until bubbles are coming again. You can keep this fruit starter until 1week in a refrigerator without feeding. and continue to keep it by every 1week feeding..
Feeding sourdough by flour and water is popular, but it needs frequent care and feeding.
Feeding fruit-starter-liquid is simple and easy.
Add water and flour to sourdough.. After 6-12 h, the mixture should have gone bubbly and doubled up again.(This step makes sourdough stronger. But you can skip this step.)