To convert yeast dough recipe to sour dough

To convert a Dry yeast recipe to use sourdough starter, you generally substitute100 grams of active sourdough starter for one 5-7g packet of dry yeast. 

However, it's crucial to adjust the recipe's flour and water content to maintain the desired dough hydration. Since sourdough starter is typically fed with equal parts flour and water (100% hydration), if you add 100g of starter, you should reduce the flour by 50g and the water by 50g from the original recipe. 

For example, if your recipe calls for 500 grams of flour, 350 grams of water, and one packet of yeast, the converted recipe would be:

• 450g flour (500g original - 50g from starter)
• 300g water (350g original - 50g from starter)
• 100g active sourdough starter 

Important Considerations:

• Longer Rise Times: Sourdough fermentation takes longer than commercial yeast. Expect the initial rise (bulk fermentation) and the proofing after shaping to take at least double the time, or even longer, depending on the temperature and the health of your starter.
• Dough Characteristics: The amount of starter can affect the dough's behavior. Using a higher percentage of starter can result in a faster rise, but might make the dough stickier, while a lower percentage offers a slower, potentially more flavorful fermentation. Experiment to find what works best for your starter and your desired outcome.
• Recipe Type: This conversion method works best for traditional yeast breads. For quick breads or other baked goods, additional adjustments may be needed. Some sources suggest adding the starter and possibly increasing the flour slightly, while others recommend reducing fat like oil alongside the flour and water adjustments. 

By following these guidelines and paying close attention to your dough as it ferments, you can successfully convert your favorite yeast recipes to sourdough and enjoy the unique flavors and textures that sourdough baking offers.