What Is the Sourdough Calculator?
The Sourdough Calculator is a baker's percentage tool designed to help you scale sourdough bread recipes to any desired dough weight. Whether you are baking a single loaf or preparing dough for multiple batches, this calculator instantly determines the exact amounts of flour, water, sourdough starter, and salt you need. It also breaks down the flour and water contributed by your starter, so you know exactly how much of each ingredient to add to the mixing bowl.
Sourdough baking relies on precise ratios rather than fixed quantities. Professional bakers use baker's percentages, where all ingredients are expressed as a percentage of the total flour weight. This system makes it easy to scale recipes up or down while maintaining the same dough characteristics. Our calculator automates this math, eliminating errors and saving time.
How Baker's Percentages Work
In baker's math, flour is always 100 percent. Every other ingredient is expressed as a percentage of the flour weight. For example, in a recipe with 75 percent hydration, 20 percent starter, and 2 percent salt:
- Flour: 100% (the base)
- Water: 75% of flour weight
- Starter: 20% of flour weight
- Salt: 2% of flour weight
If you want 500 grams of flour, you would use 375 grams of water (500 x 0.75), 100 grams of starter (500 x 0.20), and 10 grams of salt (500 x 0.02). The total dough weight would be 985 grams. This system is universal across all bread baking and allows bakers to communicate recipes regardless of batch size.
This calculator works in reverse. Instead of starting with flour weight, you enter your desired total dough weight, and it calculates the flour weight and all other ingredients for you. This is particularly useful when you know how much dough you need (for example, 900 grams for a standard loaf) but need to figure out ingredient quantities.
Understanding Hydration
Hydration is the most important variable in sourdough baking after flour quality. It refers to the ratio of water to flour, expressed as a percentage. Different hydration levels produce dramatically different breads:
- 60-65% Hydration: Stiff dough, easy to handle. Produces dense bread with a tight crumb. Suitable for bagels and some sandwich breads.
- 65-72% Hydration: Standard bread hydration. Good balance between handling and openness. Ideal for beginners and everyday loaves.
- 72-80% Hydration: The sweet spot for artisan sourdough. Produces open crumb with nice holes, chewy texture, and good oven spring. The default 75% in this calculator falls in this range.
- 80-85% Hydration: Wet dough that requires advanced handling techniques like stretch-and-folds and coil folds. Produces very open crumb when done correctly.
- 85%+ Hydration: Extremely wet dough. Reserved for experienced bakers. Can produce ciabatta-style bread with very large, irregular holes.
The right hydration depends on your flour type. Bread flour with high protein content (12-14%) can handle higher hydration because the gluten network is stronger. All-purpose flour (10-12% protein) works better at lower hydration. Whole wheat flour absorbs more water than white flour, so whole wheat recipes often use 5-10% higher hydration to compensate.
The Role of Sourdough Starter
Sourdough starter is a living culture of wild yeast and lactic acid bacteria maintained by regular feedings of flour and water. In this calculator, the starter percentage represents how much starter to use relative to the total flour weight. Common starter percentages range from 10% to 30%, with 20% being a widely used standard.
The amount of starter you use directly affects fermentation time and flavor:
- 10-15% Starter: Slower fermentation (8-12 hours at room temperature). Develops more complex, tangy flavor. Preferred for cold retarding in the refrigerator overnight.
- 15-25% Starter: Standard fermentation time (4-8 hours). Balanced flavor with mild to moderate tang. The 20% default works well for most recipes.
- 25-35% Starter: Faster fermentation (3-5 hours). Milder flavor with less tang. Useful when you need bread quickly or in cold kitchens.
An important detail that this calculator accounts for is the flour and water content of the starter itself. A standard sourdough starter maintained at 100% hydration (equal parts flour and water by weight) is 50% flour and 50% water. This means a portion of your recipe's flour and water is already present in the starter. The calculator shows "Flour in Starter" and "Water in Starter" as well as "Actual Flour to Add" and "Actual Water to Add" so you know exactly what goes into the mixing bowl.
Salt in Sourdough Baking
Salt serves multiple functions in bread baking beyond flavor. It strengthens the gluten network, controls fermentation speed, and improves crust color. The standard salt percentage for sourdough is 2% of flour weight, which translates to roughly 1.8-2% of total dough weight.
Adjusting salt within the 1.5% to 2.5% range has noticeable effects. Lower salt percentages allow faster fermentation and produce a milder-tasting bread, which some health-conscious bakers prefer. Higher salt percentages slow fermentation, strengthen the dough, and produce a more flavorful bread. Going above 2.5% can inhibit yeast activity excessively and make the bread taste overly salty.
For sourdough specifically, salt is typically added after an initial mix of flour and water (a technique called autolyse). This allows the flour to fully hydrate before salt tightens the gluten. Add salt during the first set of stretch-and-folds for optimal incorporation.
Step-by-Step Sourdough Process
Once you have your ingredient quantities from this calculator, here is a standard process for making sourdough bread:
- Autolyse (30-60 minutes): Mix the actual flour and actual water amounts. Let them rest to hydrate the flour and begin gluten development.
- Add starter and salt: Incorporate the starter and salt into the dough using pinching and folding motions until fully mixed.
- Bulk fermentation (4-8 hours): Let the dough rise at room temperature (24-27 degrees Celsius / 75-80 degrees Fahrenheit). Perform 3-4 sets of stretch-and-folds during the first 2 hours, spaced 30 minutes apart.
- Shape: When the dough has increased 50-75% in volume, pre-shape into a round, rest 20 minutes, then final shape into a boule or batard.
- Cold retard (optional, 8-16 hours): Place the shaped dough in a banneton basket and refrigerate overnight. This develops flavor and makes scoring easier.
- Bake: Preheat a Dutch oven to 250 degrees Celsius (480 degrees Fahrenheit). Score the dough, bake covered for 20 minutes, then uncovered at 230 degrees Celsius (450 degrees Fahrenheit) for 20-25 minutes until deeply golden.
Common Sourdough Mistakes and How to Avoid Them
Many sourdough issues trace back to ingredient ratios, which is exactly what this calculator helps you get right:
- Dense bread: Often caused by insufficient hydration or an underactive starter. Ensure your starter doubles in size within 4-6 hours of feeding before using it in a recipe.
- Overly sour bread: Caused by extended fermentation or too much starter. Reduce starter percentage to 10-15% and ferment at a warmer temperature for a shorter time.
- Flat loaves with no oven spring: Usually from over-fermentation. The dough should increase 50-75% in volume during bulk fermentation, not double. Use the poke test: the dough should spring back slowly with a slight indent remaining.
- Sticky, unmanageable dough: Reduce hydration by 5%. Some flours, especially fresh-milled or whole grain, behave differently than expected. Start at 70% hydration and increase gradually as you learn how your flour handles water.
Frequently Asked Questions
Below are answers to common questions about sourdough baking ratios, the calculator, and troubleshooting your bread.