How it works: All percentages are of total flour, including the flour inside the starter. Total flour = total dough ÷ (1 + hydration + salt). Starter = starter % × total flour, and its flour and water count toward hydration. Flour to add = total flour - flour in starter, split by the whole grain share. Water to add = hydration × total flour - water in starter. Salt = salt % × total flour.

On this page

From loaf size to a shopping list

Most recipes start with ingredients and leave you to discover how big the loaf turns out. This builder goes the other way. You decide how many loaves you want and how heavy each piece of dough should be, set a few percentages, and it writes the ingredient list.

That makes it handy when your banneton or tin has a known size, when you want to bake two loaves instead of one, or when you are ready to move past copying recipes and start designing your own. Everything is expressed as a share of total flour, the way professional formulas are written, so the percentages stay meaningful however large the batch.

How to build a recipe

Set Number of loaves and Dough weight per loaf. The weight is raw dough; a loaf loses roughly 10 to 15% of it as water in the oven.
Choose a Hydration. This is true hydration, so the water inside your starter is already counted.
Enter Salt, typically around 2%.
Enter Starter. The help text reminds you that it is a percentage of total flour, not of the flour you add.
Set Starter hydration to match your culture, usually 100%.
Use Whole grain flour for the share of added flour that should be whole wheat, rye or spelt. Leave it at 0 for an all-white loaf.

Under Ingredients you get the weights to measure. The lines below show the total dough, total flour and water with the starter included, what the starter itself contains, and how much of the flour was prefermented.

Worked example: two 850 g loaves

Two loaves at 850 g each, 72% hydration, 2% salt, 18% starter at 100% hydration and 15% whole grain. The builder lists:

Bread flour: 756 g
Whole grain flour: 133 g
Water: 616 g
Starter: 176 g
Salt: 20 g
Total dough: 1,700 g
Total flour, with starter: 977 g
Total water, with starter: 703 g
Starter contains: 88 g flour + 88 g water
Flour prefermented in starter: 9%

Here is how it gets there. Every ingredient is a fraction of total flour, so the whole dough weighs total flour × (1 + 0.72 + 0.02). Dividing 1,700 g by 1.74 gives 977 g of total flour. The starter is 18% of that, 176 g, and holds 88 g of flour and 88 g of water. That leaves 889 g of flour to add, split 85/15 into 756 g of bread flour and 133 g of whole grain, and 616 g of water to reach 703 g in total. Rounding each line to whole grams leaves the list 1 g heavier than 1,700 g, a difference no loaf will notice.

Why these percentages matter

Starter percentage sets the pace. More starter means more yeast and bacteria from the first minute, so bulk fermentation finishes sooner; less starter gives a slower, more forgiving rise and often a more developed flavour. Somewhere between 10 and 20% suits most home schedules.

Salt does more than season. It firms up gluten and slows fermentation slightly, which is why most bread sits close to 2%.

Prefermented flour, the 9% in the example, is the portion already fermented before mixing. It contributes acidity and flavour, and it is a useful figure for comparing formulas that are written with different starter amounts.

Tips before you mix

Build a little more starter than the list shows. The levain builder adds an allowance for what sticks to the jar.
Mix with water at the right temperature. The dough water temperature calculator works out how warm it should be for your kitchen.
Raise hydration in small steps. Going from 72% to 80% in one bake makes shaping much harder.
Whole grain flour drinks more water. Past about 30% whole grain, consider nudging hydration up a few points.
Scale by weight only. Doubling cups or spoons introduces errors that a scale avoids.

Once the recipe is set, the sourdough schedule planner turns it into a timeline that ends when you want to bake.

Recipe builder FAQ

Why is starter a percentage of total flour and not of the flour I add?

Using total flour keeps every percentage on the same base, so hydration, salt and starter all describe the whole dough. Some recipes use flour-in-the-bowl instead; the numbers look different but can describe the same bread.

How heavy should the dough be for my banneton?

A common round banneton around 22 cm across holds roughly 800 to 1,000 g of dough. Weigh a previous loaf that fitted well and use that as your starting point.

Can I use this for a loaf with no whole grain at all?

Yes. Set Whole grain flour to 0 and the flour line simply reads Flour, with no split.

The builder says the starter brings too much water. What does that mean?

With a very wet starter and a low hydration, the starter alone can hold more water than the whole dough is allowed. Lower the starter percentage, use a stiffer starter or raise the hydration.

Does the loaf weight include flour for dusting?

No. It is the dough that goes into the basket, so dusting flour and the thin film left in the bowl are extra.