Once you have the dough perfectly smooth, non-sticky and very stretchy you know you are well on the way to having a great loaf. Now you need to be patient and let the dough prove.
During proving, the gluten seems to develop further. Gas bubbles are formed by the yeast producing CO2 as it digests sugars in the flour. A long, slow proving is the best means of developing flavour in the finished bread, and it is also claimed that it reduces those components of bread that can upset some people.
I prove my bread in a food grade plastic bowl with lid, first dropping a tablespoon of oil into the bowl, dropping the ball of dough into the oil and rotating the ball to cover it in oil.
Then I put the lid on the bowl, and leave it until it doubles in size. If you prove in a warm spot, this can take as little as forty minutes, in a fridge it can take overnight.
It is necessary to stop a skin forming on the dough by it drying out. This is done by oiling it and covering it as I do, or by covering the proving bowl with a damp tea towel. If the tea towel should come into contact with the loaf, it sometimes sticks. If it does, and it is reluctant to peel off, brush the tea towel with warm water and peel it off after a little while as carefully as possible.
Now you are ready to knock back the dough.