After shaping your dough, if you place it placed seam side up in a Tupperware container or bowl and then in the refrigerator to prove for 10-24 hours, while your sourdough loaf is proving slowly in the refrigerator (rising for the second time), air bubbles inside start to rise towards the surface.
At this point, the surface is the seam side (where all your folds are). So when you take it out of the fridge and turn it over, four things happen:
1. The seam becomes the bottom of your sourdough loaf giving you a smooth underside as a lovely surface for your loaf.
2. The air bubbles that gathered under the surface of what was at the top in the fridge, are now at the bottom of the loaf. These air bubbles want to float, so they push themselves through the loaf as it’s cooking in the oven, helping your bread rise.
3. Using the refrigerator method means your dough will be firm enough to handle. Use wet hands to stop it sticking and simply lift the loaf off the baking paper, flip it over and place it back down. So easy! SKIP this step if you don’t use the refrigerator method to proof your loaf.
4. Where the dough is exposed to air (even sealed in the Tupperware) it can form a slight skin that acts as a restricting agent inside the oven, stopping the loaf from fully rising. By flipping the dough over, the ‘skin’ becomes the base of the sourdough and the underside, which was not exposed to the air and has remained moist, becomes the top of your sourdough bread, soft and ready to expand.
Be warned though!
Some baking papers stick to the dough making it impossible to pick it up and flip it. To avoid this happening, lightly spray your baking paper with oil before putting your dough onto it and into the fridge.
If your dough is showing signs of sticking. STOP. Don’t persist with it. Bake it as is without flipping. You will still get an amazing loaf!
FLIPPING YOUR LOAF
After the oven has been on for an hour, take your loaf out of the fridge. Lift it from the container using the baking paper and place it on the bench. Pick up the dough by placing one hand lightly on top and gently flip the loaf upside down and place it back down onto the baking paper. The bottom of the loaf is now facing up.
Your loaf will likely look flat, with a large top and small bottom. Don’t worry! It will magically transform in the oven.
Bake as normal, using one of these methods:
Dutch oven or casserole dish
Pizza stone
Faking it – Baking without a Dutch oven or pizza stone
