Add sourdough starter, water and yeast to a large mixing bowl.
Gently mix together until they are bubbly. Add the flour and salt to the liquid and mix through to form a shaggy dough. Allow this dough to sit for around 15 to 30 minutes or until the flour is hydrated and the dough starts to soften.
Complete a series of small stretches and folds around the bowl to bring the dough into a ball. (I've included notes and extra photos on this in the article above).
Cover the dough with a plastic cover and allow it to rise. This will take around 1 hour - but may be a little longer if it's colder at your house.
Once the dough has risen and looks smoother, tip it out onto the countertop and shape it into a batard (I have chosen batard as it's the best shape for my slow cooker).
Place the shaped dough into a banneton and allow to proof for around 15 minutes.
Turn your slow cooker onto high. Tip the dough onto a piece of parchment paper and lift it into the slow cooker.
Cook the dough on high for 1 hour. After one hour, place a dish towel under the lid and continue to cook the dough on high for another 90 minutes.
Once the bread is cooked, lift it out and allow to cool on a wire rack.