Sourdough starter feeding calculator for precise ratios and hydration
Calculate sourdough starter feeding plan
Sourdough starter feeding calculator quick guide and timing tips
This sourdough starter feeding calculator for precise ratios and hydration helps you convert any formula to a clear plan. Choose a preset like 1:2:2 for a moderate inoculation that rises predictably at room temperature, or pick custom parts to match a recipe. Final amount should cover your bake plus a small reserve to maintain the culture.
The ratio numbers represent parts by weight. With 1:2:2, every gram of seed gets two grams of flour and two grams of water, producing 100 percent hydration. Larger feedings like 1:5:5 slow the rise and suit warm kitchens. Smaller feedings like 1:1:1 peak faster and are handy when you are on a tight schedule.
- Target the total needed for levain and a spoonful to save for next time.
- Use a scale. Weight avoids the inconsistency of scooped volumes.
- Keep seed hydration in mind when switching routines. This tool assumes a typical 100 percent seed.
After calculation, the summary shows seed to keep, flour and water to add, expected hydration, and discard guidance if you currently have more starter than the seed mass required. If you want zero discard, adjust your target or ratio until the seed requirement is less than or equal to your on hand amount.
How the sourdough feeding math works
The math uses parts to split your final amount. If the ratio is a:b:c for seed, flour, and water, total parts are a plus b plus c. Seed mass equals final amount times a divided by total parts, flour mass equals final amount times b divided by total parts, and water mass equals final amount times c divided by total parts. Hydration equals water divided by flour times one hundred.
When you enter how much starter you have, the calculator compares it to the seed mass. If you have more than needed, the difference is suggested discard before feeding. If you have less, feed from what you have and reduce the plan or build in stages. Seed hydration affects precision only when you track flour and water carried in from the seed; most home bakers keep seed near one hundred percent, so this tool keeps the flow simple and practical.
Common sourdough feeding questions
Can I switch to whole grain or rye for feeds?
Yes. Expect faster fermentation and a slightly thicker texture. Keep the same parts and watch peak timing.
What if my kitchen is very warm?
Use a larger ratio like 1:4:4 or 1:5:5, keep the jar cooler, or refrigerate between feeds to avoid overproofing.
How do I scale for a big levain build?
Set a larger final amount and choose 1:2:2 or 1:3:3. Plan enough time for the build to dome and hold before mixing.