It’s still Sourdough September, and it was also GBBO‘s bread week, so today’s bake celebrates them both; I’ve made a caramelised onion sourdough loaf.
The sweet caramelised onion is a wonderful addition – and you can intensify the flavour further with the substitution of onion salt (instead of ‘plain’) to the dough.
I often find timing sourdough bread proofing stages challenging. So, although I specify rises in this recipe at room temperature, I sometimes have to put my loaf in the coldest room (believe me, it can get really chilly!) in the house for an overnight rise. Then, first thing next morning, I switch the oven on to pre-heat and get baking. This long, slow prove makes the taste of the loaf even more delicious!
We’ve had this loaf as an accompaniment to a tomato pasta dish – it makes a great mopper-upper! The following day we had what was left with goats cheese and salad.
Click here to save my caramelised onion sourdough recipe to Pinterest.


- 2 medium-sized red or brown onions, finely sliced
- knob of butter
- pinch of salt
- 450g/1lb sourdough starter (100% hydration)
- 175ml/6⅛fl oz water
- 450g/1lb strong white flour
- 7g/¼ salt
- On a medium heat, cook off the onions in the knob of butter adding a pinch of salt. Allow to brown before setting aside to cool
- Mix together the starter, water and salt
- Make a well in the centre of the flour and pour in the starter mixture
- Combine until everything is thoroughly mixed together and the dough begins to feel smooth
- Cover the mixing bowl and allow to sit for about an hour
- Fold the dough 8 times (8 single folds)
- Re-cover the mixing bowl and allow to sit for about 12 hours at room temperature or until the volume of dough doubles
- Turn out the dough out on to a lightly-floured work surface and stretch it out into a rectangle
- Spread the cooled caramelised onion mixture evenly on to the rectangle of dough
- With the short side facing you, fold the dough on to itself in four, equal lengths ensuring that the mixture runs throughout the dough
- Shape the filled dough into your preferred loaf shape (boule, batard, etc.) trying not to have any of the onion mixture poking through the top
- Place it into a well-floured (rice flour is preferred) proofing basket/banneton; cover and allow it to sit at room temperature for an hour or until doubled in size
- Preheat the oven to 260ºC/500ºF
- Once the dough is fully risen and the oven pre-heated, gently transfer the dough from the proofing basket to the baking tray, score the top of the loaf and bake at 260ºC/500ºF/Gas mark 10 for 10 minutes
- Turn the oven temperature down to 200ºC/400ºF/Gas mark 6 and bake for another 30 minutes
- Remove the loaf from the oven and put it on a wire rack to cool for at least an hour before slicing