I've been baking sourdough only a few months and have enjoyed some good results but seem to be going backwards now. Recent loaves are splitting badly, have an almost "greyish" colour rather than golden brown and scoring the loaf just prior to baking doesn't seem to help very much. I'm placing water in the oven in a small dish, setting is fan forced, bread sitting on preheated pizza stone and timing is 10mins at 220C then 25min at 190C. At tips and advice would be great. Thanks in advance.
There can be a number of causes of splitting of a loaf but looking at your photo, I wonder whether it has split at the seam because the seam was not at the bottom of the loaf.
The expansion in the oven will always take the path of least resistance and often this is through the slashes (that is the idea of having them) but it can be at the seam if the seam is not well sealed and/or not at the bottom of the loaf. For a free-form loaf it can also happen at the point of high curvature where the side of the loaf rises from the base. In a tin it will often be at the edge of the tin where the loaf over-tops the tin.
If a crust forms too early in the bake (or during proving) then once again there is the risk of a split when the bread tries to expand in the oven. In a similar vein, uneven heat in the oven can also cause 'directional' expansion towards the source of heat that can result in a break-out. The split isn't in the direction of the fan in your oven by any chance?
Other possible contributors are loaf shaping, under-proofing and low dough hydration.
Good luck with your projects.
Thanks for the feedback Farinam - I didn't realise the seam on the bottom thing was important. It did split on the side facing the fan in the oven though. I'll keep working on that proofing stage.