How to adjust the flour + water (and what it does to fermentation)

If you want to use more or less starter than your recipe calls for, the easiest method (if you don’t want to wing it!) is to:

1. Break your starter into equal parts flour and water. (Assuming a 100% hydration starter.)
2. Add up the total flour and total water in your original recipe.
3. Replace the starter with your new amount and rebalance the flour/water.

• * *

Example 1: Using less starter

Original recipe

• 80 g starter
• 400 g flour
• 300 g water
• 8 g salt

Step 1: Break down the starter

80 g starter = 40 g flour + 40 g water

Step 2: Add to the recipe totals

• Total flour: 400 + 40 = 440 g
• Total water: 300 + 40 = 340 g
• Salt stays the same
• * *

New recipe using 35 g starter

Step 3: Break down the new starter

35 g starter = 17.5 g flour + 17.5 g water

New totals

• Flour: 400 + 17.5 = 417.5 g
• Water: 300 + 17.5 = 317.5 g
• Salt: 8 g

Step 4: Compare totals to the original

Original flour total: 440 g New flour total: 417.5 g Difference: 22.5 g (≈23 g)

Original water total: 340 g New water total: 317.5 g Difference: 22.5 g (≈23 g)

Final adjusted recipe

• 35 g starter
• 400 + 23 = 423 g flour
• 300 + 23 = 323 g water
• 8 g salt
• * *

How does this affect fermentation?

• More starter = faster fermentation
• Less starter = slower fermentation
• Temperature compounds this (warm = faster, cool = slower)

If you reduce the starter and don’t want a long fermentation, use warm water. If you do want a long bulk (e.g., overnight), cool water is fine.

• * *

Example 2: Using more starter

Original recipe totals (same as above)

• 440 g flour
• 340 g water
• 8 g salt

New recipe using 120 g starter

Break down the starter: 120 g starter = 60 g flour + 60 g water

Compare to the original: Original starter flour: 40 g New starter flour: 60 g Difference: +20 g flour

Original starter water: 40 g New starter water: 60 g Difference: +20 g water

That means you remove 20 g flour and 20 g water from the base recipe to keep totals the same.

Corrected new recipe

• 120 g starter
• 400 − 20 = 380 g flour
• 300 − 20 = 280 g water
• 8 g salt

This recipe will ferment faster, because you’ve increased the inoculation (the % of starter).

• * *

Baker’s Percentages (Quick + Useful Breakdown)

Baker’s percentages are a simple way to compare recipes

(no matter how much starter you use) because all ingredients are expressed as a % of the flour.

1. Flour is always 100%

Everything else is a percentage relative to the total flour.

2. For a 100% hydration starter

• Half the starter is flour
• Half is water So you can break it down easily when calculating percentages.
• * *

Example: Your Base Recipe in Baker’s %

Base recipe:

• 80 g starter
• 400 g flour
• 300 g water
• 8 g salt

Break down the starter:

• 40 g flour
• 40 g water

Total flour = 440 g Total water = 340 g

Now calculate the percentages:

• Flour: 100% (always!)
• Water (hydration): 340 ÷ 440 = 77% hydration
• Salt: 8 ÷ 440 ≈ 1.8%
• Starter: 80 ÷ 440 ≈ 18% inoculation

So your base dough is: 77% hydration, 1.8% salt, 18% starter.

• * *

Why this matters

When you increase or decrease starter, what you’re really doing is changing the inoculation percentage.

• Higher % starter = faster fermentation
• Lower % starter = slower fermentation

If you keep the flour + water totals the same, your hydration stays the same, so the dough feels familiar even with different fermentation speeds.

• * *

Quick Formula to help you calculate!

Baker’s % = (ingredient weight ÷ total flour weight) × 100

I hope all of this information helps you rather than confuses you more. My base country loaf recipe is linked here! Happy baking, Early Risers!