White Sourdough Bread

My sourdough starters are alive and well and are maturing with every use and replenishment.
They sit happily in the refrigerator and each time I make a loaf I replenish them at a 100% hydration rate, i.e. equal parts water and flour, so if I take out 300 gms of starter, I replenish with 150 gms water : 150 gms flour, leave it for a few hours to reactivate and put it away in the refrigerator.

Since I made the starters, I have been baking various loaves, with varying degrees of success. All of the loaves have been good, but some better than others. The wholemeal loaves have been the most successful, and I recently baked a 7 grain & honey wholemeal loaf which was dubbed as excellent by those who tasted it.

White sourdough is the one giving the most grief, so after a little more research I tried the following:--

1) Thoroughly mix flour, oil, sugar and sourdough starter and water together.
2) Autolyse for 20 minutes
3) Add salt and knead for 10 to 15 minutes to form a smooth, well structured dough
4) Cover and leave to rise 4 --6 hours until the dough feels spongy and is well developed.
5) Every hour or so fold the dough over on itself by taking the edges and folding them over working around the bowl.
6) When the ferment is finished and the dough has risen and feels nice and spongy, shape into a loaf or 
loaves. Don't be too vigorous here as you do not to knock the dough down, but rather you want to maintain the structure.
7) Place the loaf into a bread tin or alternatively upside down in a lined banneton and retard by placing in the fridge overnight.
8) Next morning remove from fridge and allow to warm up and  finish it's proof. This will take approx1--3 hours depending on ambient temperatures.
9) When it appears that the final proof is well underway, preheat your oven and bake.
10) For a 1 kg dough, I baked for 45 mins at 230C.

I set up a makeshift bakers oven in my hooded barbecue using clay pavers and a tray of water for steam injection. I actually baked two loaves at differing times, the first loaf (pictured) came out beautifully, however, the underside of the second loaf was overcooked, so next time, I will cook both at the same time.