What is this?
This calculator tells you how much flour and water to add to an existing starter to reach a target total weight of active starter. It assumes you want a final starter at a known hydration (default 100% = equal weights of water and flour). Accurate weighing with a Digital Kitchen Scale is essential for reliable results.[1][2]
Why important: Scaling starter correctly prevents over-thinning or overly stiff starter, ensures predictable fermentation times, and lets you build just the right amount for a recipe without waste.[1][2]
Calculator
🛒 Recommended Products
We recommend the following tools for this recipe:
Digital Kitchen Scale
Essential for accurate starter measurements and feed calculations
Glass Jar for Starter
Clear vessel for monitoring rise and activity
Jar Spatula
Helps scrape starter from jar walls without contamination
Clear Straight-Sided Container
Use for bulk builds where you need accurate volume and height tracking
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Recommendations by Flour Type
| Flour | Min % | Standard % | Max % |
|---|---|---|---|
| Maintain small daily builds | 2% | 4% | 10% |
| Baker's preference for larger builds | 10% | 10% | 20% |
| For recipe-scale amounts, plan staged builds | 20% | 50% | 100% |
Hydration Ranges
Fast to peak, uses little flour; good for daily maintenance.
Useful for most home recipes; predictable timing when your starter is active.
Use staged refreshes to avoid long lag phases and to maintain activity.
Plan multiple feed cycles and use a Clear Straight-Sided Container or larger vessel to monitor rise.[1][2]
Tips
💡 Weigh precisely
Always weigh starter, flour and water on a Digital Kitchen Scale. Small errors scale up during builds and change timing significantly.[1][2]
💡 Use the right vessel
A Glass Jar for Starter or a Clear Straight-Sided Container lets you see rise and fall; mark the level before and after feeding to track activity.[1]
💡 Mixing and scraping
Use a Jar Spatula to incorporate dry flour from the walls and ensure even hydration—this prevents pockets of dry flour that slow fermentation.[1][2]
💡 Temperature and timing
A refreshed starter at 24–26°C will peak faster than at cooler temperatures. Adjust your build size if you need it to peak at a specific time for baking.[1][2]
💡 Staged builds for large quantities
Instead of a single huge feed, refresh in two stages (e.g., 1:4 then 1:5) to keep the culture active and predictable.[1][2]
💡 Include starter water/flour in recipes
When you use starter in dough, remember its flour and water contribute to the dough formula—account for it using your recipe's baker's percentages.[1][2]