Helps home bakers calculate exact sourdough starter feeding ratios and timing. Adjusts for your current starter amount, desired peak time, and flour type. No more guesswork when maintaining a healthy active starter.
🍞 Sourdough Starter Feeding Calculator
Feeding Results
How to Use This Tool
Follow these simple steps to get accurate sourdough starter feeding calculations:
- Enter the amount of active sourdough starter you currently have, and select whether you measured by grams or cups.
- Choose your preferred feeding ratio from the dropdown menu. The 1:1:1 ratio is standard for daily maintenance.
- Select the type of flour you will use for feeding, as different flours ferment at different rates.
- Enter your room temperature and select Celsius or Fahrenheit to get accurate peak time estimates.
- Optionally enter your desired peak time (how many hours until you need the starter to be active) to see if your selected ratio matches your schedule.
- Click the Calculate button to see detailed feeding measurements and timing.
- Use the Reset button to clear all inputs and start over, or Copy Results to save your calculations.
Formula and Logic
This calculator uses standard sourdough starter feeding ratios and fermentation science to generate results:
- Feeding Amounts: Based on your selected ratio (starter:flour:water), it calculates the exact grams or cups of flour and water to add. For example, a 1:2:2 ratio means for every 1 part starter, add 2 parts flour and 2 parts water.
- Unit Conversions: If you use cup measurements, the calculator converts to grams using standard weight conversions for sourdough starter and flour types, then converts results back to cups for your convenience.
- Peak Time Estimation: Uses a base peak time of 5 hours at 22°C (72°F) for all-purpose flour, adjusted for room temperature (20% faster/slower per 5°C difference from 22°C) and flour type (rye peaks 20% faster, whole wheat 10% faster).
- Hydration: Calculated as (water weight / flour weight) * 100, reflecting the hydration level of the added ingredients.
Practical Notes
These real-world tips will help you get the most out of your sourdough starter feeding routine:
- Always use active, bubbly starter for feeding — discard starter that has separated or has a dark liquid (hooch) on top first.
- Weight measurements (grams) are far more accurate than volume (cups) for sourdough baking. A small kitchen scale is a worthwhile investment for consistent results.
- Whole grain flours (rye, whole wheat) have more natural yeasts and nutrients, so your starter will peak faster than with refined flours.
- If your kitchen is warmer than 25°C (77°F), check your starter 1-2 hours earlier than the estimated peak time to avoid over-fermentation.
- For long-term storage, feed your starter 1:1:1, let it peak, then refrigerate for up to 1 week before feeding again.
Why This Tool Is Useful
Maintaining a sourdough starter can be tricky for home bakers, especially when adjusting for different flours, temperatures, and schedules:
- Eliminates guesswork for feeding ratios, reducing waste from over-feeding or under-feeding.
- Adjusts for real-world variables like room temperature and flour type, which generic calculators often ignore.
- Helps you plan baking schedules by estimating peak times accurately, so your starter is ready when you need it.
- Supports both weight and volume measurements for bakers at any skill level, from beginners using cups to advanced bakers using scales.
Frequently Asked Questions
What is the best feeding ratio for daily starter maintenance?
The 1:1:1 ratio (equal parts starter, flour, water) is the standard for daily maintenance at room temperature. It keeps your starter active without becoming too large or too hungry between feedings.
Can I use this calculator for gluten-free sourdough starter?
This calculator is optimized for wheat-based and rye starters. Gluten-free starters (made with rice, buckwheat, or sorghum flour) ferment at different rates, so results may not be accurate. Adjust peak time estimates by 30-50% for gluten-free flours.
How do I know when my starter has peaked?
A peaked starter will have risen to 1.5-2x its original size, have a domed top, and start to show small bubbles breaking on the surface. It will smell pleasantly tangy, not like alcohol or vinegar.
Additional Guidance
For best results with your sourdough starter:
- Feed your starter at the same time each day to establish a consistent fermentation rhythm.
- Use filtered or dechlorinated water for feeding, as chlorine can kill the natural yeasts in your starter.
- If your starter develops a dark liquid (hooch) on top, it means it is hungry — feed it immediately with a 1:2:2 or 1:3:3 ratio to strengthen it.
- Label your starter jar with the last feeding time and ratio to avoid confusion, especially if you have multiple starters.