How to Scale Any Sourdough Recipe

You've got a recipe you love. It makes one loaf and you need three. Or it makes three and your Dutch oven is sized for one. Scaling sourdough sounds like simple multiplication until you double the starter and your dough is blown out by noon. Here's how to do it properly, three different ways, depending on what you're actually trying to hit.

We'll go through three practical ways to scale:

• by flour weight
• by total dough weight
• by number of pieces and piece weight

And we'll cover the part most guides skip: how starter percentage changes timing.

If you want to jump straight into the math, the easiest route is the sourdough recipe calculator.

Calculator

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mode switcher showing the three entry modes as tabs

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Why "just double it" breaks sourdough

The trap is thinking sourdough recipes are just lists of gram amounts.

They're not. Underneath, they're ratio systems.

Flour is the anchor. Everything else is usually expressed as a percentage of flour. That's baker's percentage, and if you haven't worked with it much yet, this quick guide on baker's percentage will make the whole thing click.

Here's the short version. If a recipe has:

• 500g flour
• 375g water
• 100g starter
• 10g salt

then the percentages are:

• water: 75%
• starter: 20%
• salt: 2%

That matters because scaling should start with the percentages, not with blind multiplication.

Why? Because one ingredient has a job beyond flavor or structure.

Starter drives fermentation speed.

If you take a recipe that uses 10% starter and bump it to 25% because you want things to move faster, that's a real choice. Same if you double a recipe and also double the starter while expecting the exact same timeline. You may still get good bread, but your dough might peak earlier than you planned.

So yes, you can multiply a sourdough recipe. But the smart way is to understand the percentages first, then decide whether you want the same timing or a different one. The same logic applies if you want to scale a bread recipe of any kind, not just sourdough. Ratios first, grams second.

Pick your entry point

There are three useful ways to resize a sourdough recipe, and each starts from a different question.

1. Scale by flour weight. Use this when you know how much flour you want to use. Classic baker thinking. You pick the flour amount, and the rest follows from the percentages.

2. Scale by total dough weight. Use this when your vessel decides for you. Maybe your Dutch oven likes 900g of dough. Maybe your loaf pan wants something smaller. You start with the final dough weight and work backward.

3. Scale by pieces and piece weight. Use this for pizza balls, rolls, buns, and baguettes. You know how many pieces you want, and how heavy each one should be.

That's why one calculator mode never feels like enough. Different baking days ask different questions.

If you're ready to plug in your own formula, head to the calculator and choose the mode that matches your goal.

Scale by flour weight

This is the classic method.

You decide your flour weight first. Then you apply each ingredient percentage to that flour weight.

Let's use a simple base recipe at 500g flour:

Now let's say you want to scale that recipe to 1000g flour instead of 500g.

Easy. Keep the percentages the same.

New total dough weight: 1970g.

Nothing fancy there. You just preserved the formula.

This method is great when you buy flour in bulk and want to use a set amount, when you mix around a stand mixer capacity, when you already think in percentages, or when you're tuning hydration and want tight control.

One note on hydration. If you change flour weight but keep hydration percentage fixed, your dough behavior stays broadly similar. If you also want to tweak hydration while scaling, use the sourdough hydration calculator to keep the math clean.

The biggest advantage of flour-first scaling is clarity. Flour stays the anchor. Every other ingredient falls into place fast.

If that's how your brain works, use the calculator in flour-weight mode and let it do the repetitive part.

Calculator

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flour-weight mode, input total flour, output scaled recipe

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Scale to a target dough weight

Sometimes you don't care how much flour is in the recipe.

You care that the final dough weighs 900g. Or 750g. Or 1100g.

This is common when you're baking in a Dutch oven, a loaf pan, or a combo cooker that has a sweet spot.

For many home bakers, these rough targets work well:

• 750g dough for a smaller loaf
• 900g dough for a standard Dutch oven loaf
• 1100g dough for a larger loaf with more height and spread resistance

To resize a sourdough recipe this way, you first need the total formula percentage.

Using the same formula:

• Flour: 100%
• Water: 75%
• Starter: 20%
• Salt: 2%

Total percentage = 197%

Now say you want 900g total dough.

Work backward:

In decimal form, 197% becomes 1.97.

So:

Now calculate the rest:

That's the whole trick. Find the flour from the total formula percentage, then rebuild the formula from there. Small rounding differences of a gram or two are normal.

This method is perfect when your baking vessel has a known ideal load, when you want consistent loaf size every bake, or when you're adapting recipes from books that make awkward batch sizes.

It's also handy if one recipe produces a loaf that always feels too squat or too massive in your setup. Instead of guessing, you set the dough weight on purpose.

If you want to skip the backward math, use the sourdough recipe calculator and choose total-dough-weight mode.

Calculator

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total-dough-weight mode, input target dough weight, output scaled recipe

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Scale by pieces and piece weight

This is the most useful method for pizza night, dinner rolls, buns, and baguettes.

You start with the number of pieces you want and the target weight for each piece.

Say you want 8 pizza balls at 260g each.

First, find the finished dough you need:

Now add a little extra for dough stuck to the bowl, bench flour, scale residue, and trimming. A small loss allowance helps a lot here.

For most home baking, 3% to 5% extra dough is enough.

Let's use 4%. The cleanest way to build in a loss factor is to divide by 0.96, so the pieces you actually finish with still hit their target weight:

Now use a sourdough pizza formula:

• Flour: 100%
• Water: 63%
• Starter: 10%
• Salt: 2%
• Total formula: 175%

Find flour weight:

Then scale the ingredients:

That gives you enough dough to divide into 8 pieces of about 260g each, with a little safety margin.

This is the mode to use when you need exact pizza ball weights, when you're making rolls for a holiday table, when you want baguettes that proof and bake evenly, or when you just hate coming up one piece short.

A tiny loss factor is what makes this method feel practical instead of theoretical. Especially with smaller pieces.

If you want to run the numbers quickly, the calculator has a pieces mode for exactly this.

Calculator

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pieces mode, input piece count and weight per piece, output scaled recipe

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The salt rule nobody should break

Salt stays tied to flour.

Always.

If your recipe uses 2% salt, that means 2% of flour weight. Not 2% of total dough weight. Not a random spoonful because the batch looks bigger. Flour weight.

Examples:

• 500g flour → 10g salt
• 1000g flour → 20g salt
• 1500g flour → 30g salt

That's the rule. Simple. Reliable. Worth memorizing.

Weigh your salt. Don't eyeball it. If your loaf tastes flat after scaling, salt is one of the first things to check.

Hydration doesn't scale, it stays put

Same idea as salt.

75% hydration is 75% hydration whether you're making a single boule or a sheet pan focaccia. The percentage doesn't change when the batch gets bigger.

This matters because dough feel should stay consistent after scaling. If your new batch feels wetter or drier than the original, something got mismeasured. Percentages are how you keep feel constant across sizes.

If you want to tune hydration while scaling, the sourdough hydration calculator keeps the math honest.

Starter math is where people lose it

This is the part that confuses almost everyone at first.

Starter scales as a percentage of flour too. But unlike salt, starter does more than season the dough. It changes the pace.

More starter usually means faster fermentation. Less starter usually means slower fermentation.

So when you scale a sourdough recipe, there are really two separate questions:

1. How much dough do I want?
2. Do I want the same schedule?

If you want the same style of fermentation timing, keep the starter percentage the same while scaling up or down.

For example, if your original recipe uses 20% starter, and you double the flour, keeping starter at 20% will usually keep you in a similar timing zone at the same temperature.

If you change the starter percentage, you change the clock.

Rough ballpark at about 75°F with an active starter:

Exact times depend on your starter strength, flour choice, dough temperature, and room temperature. Still, the direction is consistent.

The key point is this: starter percentage is a timing control knob.

So if you scale a recipe from one loaf to three and want your day to feel the same, keep the starter percentage the same. If you want a longer, more relaxed schedule, lower the starter percentage on purpose. If you need the dough to move sooner, raise it on purpose.

That's also why a good sourdough recipe converter needs to account for percentages, not just ingredient multiplication. If you want a deeper look at how starter behaves, head to the starter guide.

Why your bulk time barely changes when you double the batch

This is one of the most useful myths to let go of.

If you double the dough, bulk fermentation does not usually double.

Fermentation is driven mostly by dough temperature, room temperature, starter activity, starter percentage, and flour choice. Not by the simple fact that there is more dough in the bowl.

A 1kg batch at 76°F and a 2kg batch at 76°F often ferment on a pretty similar timeline if the formula stays the same. The ratio of microbes to flour is identical, because you scaled by percentage. The temperature is identical. The chemistry is identical.

The one real variable is thermal mass. A bigger dough has less surface area relative to its volume, so it loses heat more slowly and retains the warmth fermentation generates better. That nudges a very large batch a touch faster toward the end of bulk. Not because it's big. Because it's slightly warmer than its smaller sibling. The practical difference is usually 15 to 30 minutes on batches under 4 to 5kg. Not doubled. Not tripled.

So if your one-loaf batch bulks in 5 hours, your two-loaf batch will usually finish in roughly the same window. Sometimes a little sooner, since the bigger mass holds fermentation heat better. If you're seeing closer to 10 hours, something else changed. Colder flour or water. A sluggish starter. A cooler kitchen than you think.

This matters because people often scale up and then wait far too long, expecting volume alone to slow everything down. It usually doesn't.

Watch the dough. Not the clock alone. Look for the signs you normally use: some rise in the container, a smoother airier feel, visible fermentation bubbles, better elasticity and liveliness. That's what tells you bulk is moving along.

Practical batch limits at home

One last real-world note.

You can scale almost any formula on paper. Your kitchen may still vote no.

A few limits show up fast:

• your mixing bowl size
• your stand mixer capacity (most home mixers strain above 1.2 to 1.5kg of flour)
• your ability to develop dough by hand (most people top out around 1.5 to 2kg of dough)
• fridge space for cold retard
• Dutch oven count
• oven capacity if baking multiple loaves

A formula that works beautifully at 900g total dough might get annoying at 4kg if your bowl is cramped and your folds feel clumsy. The honest ceiling for most home setups is around 2 to 2.5kg of flour per session.

So yes, use the math. But also respect the gear.

If a batch feels too big to handle comfortably, split it into two tubs or mix in rounds.

Good scaling isn't just correct. It's workable.

The simple way to think about it

Here's the whole idea in one pass.

• Scale sourdough from percentages, not from guesswork
• Salt stays locked to flour weight
• Hydration stays locked to flour weight
• Starter also scales by percentage, but it changes fermentation speed
• Flour weight mode is best when flour is your starting point
• Total dough weight mode is best when your baking vessel sets the target
• Pieces mode is best for pizza, rolls, and baguettes
• Doubling dough rarely means doubling bulk time

Once that clicks, scaling gets a lot less mysterious.

Pick the recipe you bake most. Pull out its baker's percentages. Run it through the calculator at the weight you actually want. Bake it once at the new size and take notes on bulk time. You'll find it's a smaller shift than you expected.

And if your starter's been sluggish and that's what's really throwing the timing off, the starter guide is the place to go next.