I have been making bread for some time using a fairly standard recipe - 500g bread flour, 300g water, fast acting dried yeast, with small quantities of salt, sugar and butter or olive oil. The bread is cooked in a tin.
Recently I have had problems with the bread sinking immediately on putting into the oven - temperature 200°C, about 400°F. It sinks about 10 - 20% resulting in very heavy bread. This happens randomly, about 1 in 3 or 4 times.
I wonder if a fan oven is worse than a conventional oven for making bread.
Any help would be greatly appreciated.