Place the water in the bowl of a stand mixer. Add yeast and leave for 5 minutes.
Mix salt, butter, vitamin C and flour together in a separate bowl. Add it to the yeast mixture. Using the dough hook, knead on low speed for 6 to 7 minutes. The dough should be firm and stretchy.
Roll the dough into a ball and place into a lightly greased bowl. Cover with cling film and leave in a warm place for 1 hour. It should have more than doubled in size.
Turn out the dough and knock it back for a few seconds. Then transfer it to a loaf tin and leave covered for 40 minutes.
Preheat the oven to 225 C / Gas 7 for 20 minutes. It is important that that oven is properly preheated.
Bake the loaf until golden, about 30 minutes. Carefully turn out the bread while still hot and you can check if it's done by tapping the bottom of your loaf, it will sound hollow when done. Allow to cool before cutting.