Sourdough Baking Guide: Starter, Dough, and Crusty Loaves
The first time you pull a steaming, blistered sourdough loaf from the oven and hear its crust crackle as it cools, you will understand why bakers dedicate years to perfecting this craft. Sourdough is the oldest form of leavened bread, relying on a symbiotic culture of wild yeast and lactic acid bacteria rather than commercial yeast. The result is bread with a complex, tangy flavor, a chewy crumb with irregular holes, and a crust that shatters when bitten. Learning sourdough requires patience — your starter needs days to become active, and each loaf demands attention across two days — but the rewards are loaves that no store can replicate. Even your first imperfect loaf will taste better than anything from a bakery shelf.
Understanding the Sourdough Starter
A sourdough starter is a living ecosystem of wild yeast and bacteria that you feed and maintain like a pet. The wild yeast, primarily Saccharomyces cerevisiae strains that occur naturally on grain and in the air, produces carbon dioxide that leavens the bread. The bacteria, mainly Lactobacillus species, produce lactic and acetic acids that give sourdough its characteristic tang and also preserve the bread naturally. These two organisms exist in a delicate balance. The bacteria create an acidic environment that suppresses undesirable microorganisms, while the yeast provides the gas that lifts the dough. Maintaining this balance is the central task of sourdough baking.
Creating a Starter from Scratch
Mix equal parts whole wheat or rye flour and water by weight — 100 grams each is a good starting quantity. Whole grain flours contain more wild yeast and bacteria than white flour, so they ferment more reliably. Cover the container loosely and leave it at room temperature, 70 to 75 degrees Fahrenheit, for 24 hours. The next day, discard half the mixture and feed it with fresh flour and water in equal parts. Repeat this discard-and-feed cycle daily. Within three to seven days, you should see bubbles forming and the starter should develop a pleasant, fruity, or yogurt-like aroma. A ripe starter doubles in volume within four to eight hours after feeding, floats in water, and smells tangy rather than sour or alcoholic.
Feeding Schedules and Ratios
The feeding ratio determines how quickly your starter matures. A 1-to-1-to-1 ratio — equal parts starter, flour, and water by weight — produces the fastest fermentation and is ideal for daily bakers. A 1-to-2-to-2 or 1-to-5-to-5 ratio slows fermentation and allows you to feed less frequently. For a 1-to-5-to-5 feeding, combine 20 grams of starter with 100 grams of flour and 100 grams of water. This lean feeding produces a milder flavor because the bacteria have less food relative to the yeast population. For a tangier loaf, use a lower feeding ratio or refrigerate your starter between feedings, which favors acid production.
Maintaining a starter at room temperature requires daily feedings. If you bake less frequently, store the starter in the refrigerator and feed it once per week. To bring a refrigerated starter back to activity, take it out, feed it at room temperature for two or three cycles, and it will be ready for baking within 24 hours. A healthy starter should roughly double in volume within six to eight hours after a 1-to-1-to-1 feeding at room temperature.
The Sourdough Baking Process
Sourdough baking follows the same fundamental steps as commercial yeast bread but on a longer timeline. Where a yeasted loaf might go from mixing to oven in three hours, a sourdough loaf typically takes 12 to 24 hours from start to finish. Most of that time is hands-off fermentation.
Mixing and Autolyse
Combine your flour and water and let them rest for 30 to 60 minutes before adding the starter and salt. This rest period, called autolyse, allows the flour to fully hydrate and the gluten to begin developing without the interference of salt or acid. A proper autolyse produces dough that is easier to stretch and shape later. After the autolyse, add your active starter and salt, then mix by folding the dough over itself until everything is evenly incorporated. The dough will feel shaggy and wet at this stage. That is normal for sourdough, which typically uses higher hydration levels than yeasted bread.
Bulk Fermentation
Bulk fermentation is the most critical phase and the hardest to master. During this three-to-five-hour period, the dough rises and develops flavor and strength. Instead of kneading, use a series of stretch-and-folds. Every 30 minutes during the first two hours, wet your hands, grab one side of the dough, stretch it upward, and fold it over the top of the dough. Rotate the bowl and repeat on all four sides. These folds strengthen the gluten network without deflating the gas bubbles. The dough should visibly increase in volume, show bubbles on the surface, and feel airy and puffy by the end of bulk fermentation. Under-fermented dough produces dense, flat loaves. Over-fermented dough becomes sticky, slack, and difficult to shape.
Shaping and Proofing
Turn the fermented dough onto a lightly floured surface and shape it into a round boule or an oval batard. The key is creating surface tension on the outside of the dough by tucking the edges underneath and dragging the dough across the surface to tighten the skin. A well-shaped loaf holds its form and resists spreading. Place the shaped dough seam-side up in a floured banneton or a bowl lined with a floured kitchen towel. Cover and refrigerate for 8 to 16 hours. This cold proofing slows fermentation, deepens the flavor, and makes the dough firm enough to score cleanly. For tips on understanding yeast fermentation more broadly, see our yeast baking guide.
Scoring and Baking
Preheat your oven with a Dutch oven or baking stone inside to 500 degrees Fahrenheit for at least 30 minutes. Turn the cold proofed dough onto a piece of parchment paper. Score the top with a sharp lame or razor blade, cutting about a half-inch deep at a 30-degree angle. The score marks control where the bread expands during the first few minutes of baking, producing the characteristic ear or bloom. Without scoring, the bread will burst unpredictably.
Bake with the lid on for 20 minutes, then remove the lid, reduce the temperature to 450 degrees, and bake for another 20 to 25 minutes until the crust is deep amber. The internal temperature should reach 205 to 210 degrees Fahrenheit. Cool the bread on a wire rack for at least two hours before slicing. Cutting into a hot loaf releases steam and produces a gummy, unappealing crumb.
Maintaining Hydration and Dough Consistency
Hydration percentage — the ratio of water to flour by weight — is the defining variable in sourdough baking. A 70 percent hydration dough uses 700 grams of water for every 1,000 grams of flour. Higher hydration doughs above 75 percent produce more open crumb structures with larger irregular holes but are stickier and harder to handle. Lower hydration doughs around 65 percent are easier to shape and produce a tighter, more sandwich-friendly crumb.
Beginner bakers should start around 70 percent hydration. This level produces a manageable dough that still yields an open crumb. As you gain confidence, increase the hydration gradually. Each five percent increase changes the dough behavior noticeably and requires adjustments to your folding and shaping technique. The flour you use also affects hydration. Whole wheat and rye flours absorb more water than white flour, so doughs made with these flours need higher hydration percentages to achieve the same consistency.
Troubleshooting Common Sourdough Problems
Sourdough baking presents challenges that commercial yeast baking does not. The longer fermentation times and reliance on a living starter introduce more variables.
A dense, flat loaf with no rise usually means the starter was not active enough. Your starter should double within four to six hours of feeding before you use it. A float test — dropping a spoonful of starter into water to see if it floats — is a reliable indicator of readiness. If the starter does not float, feed it for two or three more cycles before baking.
A gummy or sticky crumb indicates under-baking or cutting the bread too soon. Bake until the internal temperature reaches at least 205 degrees and cool completely before slicing. Gummy crumb can also result from flour that was ground too coarse, which prevents full starch gelatinization.
A loaf that spreads sideways instead of rising upward needs more gluten development during bulk fermentation or a tighter shape. Add more stretch-and-folds during the first two hours of bulk fermentation and create firmer surface tension during shaping.
A sourdough loaf that is too sour can be adjusted by using a higher feeding ratio, shortening the bulk fermentation, or using more white flour. Sourness comes from acetic acid produced by the bacteria during long, cool fermentation. For a milder flavor, keep your starter at room temperature with more frequent feedings and reduce the cold proofing time.
Frequently Asked Questions
How long does it take to create a sourdough starter from scratch?
A new starter typically takes five to ten days to become reliably active. Factors like room temperature, flour type, and the natural yeast population in your kitchen affect the timeline. A starter is ready when it doubles in volume within four to six hours after a 1-to-1-to-1 feeding, smells pleasantly tangy, and passes the float test. If your starter shows no activity after ten days, try switching to whole rye flour, which has more natural yeast than other flours.
Can I keep my sourdough starter in the refrigerator?
Yes. Refrigerating your starter slows fermentation and reduces feeding frequency to once per week. Before baking, take the starter out, feed it at room temperature, and wait for it to become active again — usually two or three feedings over 12 to 24 hours. Long-term refrigeration can favor acid-producing bacteria over yeast, making your starter more sour over time. If this happens, feed it more frequently at room temperature for a few days to rebalance the population.
Why is my sourdough bread so dense?
Dense sourdough usually results from inactive starter, under-fermentation, or under-hydration. Ensure your starter is at peak activity before mixing. Extend bulk fermentation until the dough is visibly puffy and aerated, not just slightly larger. If your dough feels stiff, increase the hydration by five percent. For troubleshooting other bread types, our bread baking basics guide covers foundational techniques that apply to sourdough as well.
What is the best flour for sourdough baking?
Bread flour with 12 to 14 percent protein produces the strongest gluten network and the best rise. A blend of 80 percent bread flour and 20 percent whole wheat flour offers a good balance of structure and flavor. For your starter, whole rye or whole wheat flour provides more nutrients for the yeast and bacteria. Many experienced bakers maintain their starter on whole grain flour but bake their loaves primarily with white bread flour.
Conclusion
Sourdough baking rewards patience and attention. The living starter, the long fermentation, and the hands-on techniques of folding, shaping, and scoring connect you to a bread-making tradition that predates commercial yeast by thousands of years. Your first few loaves may be imperfect, but each one teaches you something about how the dough behaves and how your starter responds to temperature, feeding, and timing. Once you develop a feel for the process, you can adapt hydration levels, experiment with different flour blends, and create signature loaves that reflect your own kitchen environment. For more foundational bread techniques, explore our bread baking basics guide and our yeast baking guide, and equip yourself properly with the right tools from our baking tools and equipment guide. The perfect crusty loaf is not about following a recipe rigidly. It is about learning to read the dough and trust your instincts.