Sunday sourdough baking

We bought a sourdough yeast starter from ebay for £5 months ago, and I try to bake a loaf every Sunday. I use a very simple recipe which consists of: 300g strong white bread flour, 100g rye or whole meal flour, 1tsp salt, 200g starter and between 77% - 80% hydration (depending on how careful I am when it comes to measuring out water).

Today's loaf is okay; I have made nicer looking ones before. The dough got slightly stuck on the bannetone (which was very well floured) as I was trying to tip it out, hence the loaf's flatness. Nonetheless, it still has a nice texture and sourness to it.