Sourdough Bread Lab · Calculator

Design your own sourdough bread

The sliders start at the typical loaf: the median of 152 recipes for each ingredient, in grams per 100 g of flour. Move any of them within the range that 90% of recipes use (the 5th to the 95th percentile) and the grams update, with where your choice sits among the recipes and what that ingredient does.

This scales ratios; it is not a tested recipe. Each ingredient moves on its own against the flour, and a combination no recipe uses may not bake the way you expect. For the method, pan and oven, follow the real recipes nearest your numbers.

Flour

Flour weight (g)

500 g, about 4 cups, makes one typical loaf.

Start from a recipe

Load a real recipe's percentages into the sliders. Search by title or site.

Grams per 100 g of flour

Starter
125 g · 25%
In the middle: 46% of recipes use more, 48% less.
Active starter by flour weight. More starter rises faster and tastes milder; less starter needs a longer, sourer ferment. Its own flour and water are not counted in the other numbers.
Water
340 g · 68%about 1 1/2 cups
In the middle: 50% of recipes use more, 50% less.
Water added to the dough, the main hydration lever: higher water gives the open, irregular crumb and is harder to shape.
Salt
10 g · 2%
In the middle: 39% of recipes use more, 40% less.
About 2% of the flour, the bread standard.
Fat
none · 0%
None, like 85% of recipes.
Most country loaves use none; sandwich-style sourdough adds butter or oil.
Sweetener
none · 0%
None, like 82% of recipes.
Usually none; sandwich loaves add a little honey.

Your sourdough bread

Your sourdough bread in grams, with approximate volumes
Ingredient	Grams
Flour	500 gabout 4 cups
Starter	125 g
Watermilk, buttermilk, yogurt, cream and water	340 gabout 1 1/2 cups
Salt	10 g
Fatbutter, oil and shortening	none
Sweetenerwhite sugar, brown sugar, honey and syrups	none
Total	975 g

975 g in all from 500 g of flour, counting only the groups above.

Closest real recipe: Same Day Sourdough Bread (biggerbolderbaking.com).

BakeThe median of 128 recipes is 450°F (230°C), most for 20 to 40 minutes at their own size. A bigger or smaller batch, or a different pan, changes the time.

The 3 real recipes nearest your numbers

Measured on starter, water, salt, fat and sweetener at once. These are published, tested recipes: follow one for its method, pan and timing, or load its percentages and adjust from there.

1
Same Day Sourdough Bread · biggerbolderbaking.com
starter 25% · water 69% · salt 1.9% · fat 0% · sweetener 0%
2
Slow Cooker Sourdough Bread · littlespoonfarm.com
starter 23% · water 69% · salt 2.1% · fat 0% · sweetener 0%
3
Beginners Sourdough Bread · farmhouseonboone.com
starter 21% · water 68% · salt 2.1% · fat 0% · sweetener 0%

How the calculator works

Every recipe is reduced to baker's percentages: grams of each ingredient group per 100 g of flour. The starting point is the median of all 152 recipes for each group separately, so no single recipe is exactly the starting loaf. Grams are your flour weight times each percentage, rounded to the nearest 5 g above 50 g and the nearest gram or half gram below.

“More than 80% of recipes” counts the recipes with strictly less of that ingredient per gram of flour. The nearest recipes are measured on every ingredient at once, each scaled by how much recipes vary on it, so a wide-ranging ingredient does not outweigh a narrow one.

Only the groups listed are counted. Vanilla, spices, mix-ins and toppings are left out unless they have their own slider. Volumes are approximate: flour at 125 g a cup, sugar 200 g, butter or oil 225 g, milk and other liquids 240 g.