My foolproof method for making an active sourdough starter!
Spoon 50g of the mixture into a clean pint jar, and add another 50g flour and 50g water, stirring them together. Replace the loose fitting lid as before. Discard the excess starter, or save it in the fridge to make sourdough crêpes or some other delicious wonder later!
You can mark the outside of your jar at the level of your freshly fed starter with painter's tape or a rubber band so that you can easily see how much your starter has risen each day.