S.D Timer

S.D TIMER computes the exact feeding schedule for your sourdough starter, working backward from your target ready time to give you a precise feed time and gram-level recipe.

HOW IT WORKS

Enter six parameters: target ready time, quantity of starter needed (grams), desired hydration percentage, flour type, starter activity level (%), and ambient temperature (°C or °F). The app applies a fermentation kinetics model that factors temperature-dependent metabolic rates of lactic acid bacteria and wild yeast to calculate when your starter will hit peak activity.

OUTPUT — YOUR FEEDING PLAN

• Feed time: the exact moment to feed so your starter peaks on schedule
• Starter / flour / water quantities in grams
• Feed ratio (e.g., 1:9.8:9.8)
• Estimated peak pH
• Predicted flavor profile (mild, balanced, tangy, complex)
• Recommended bread types suited to the resulting starter profile
• Fermentation timeline chart with 80% activity window marked

Set process alarms directly from the results screen to get notified at feed time and at peak.

DESIGNED FOR PRECISION

Temperature has a nonlinear effect on fermentation speed. A 5°C difference between summer and winter kitchens can shift peak time by 2–4 hours. S.D TIMER accounts for this so your timing stays consistent regardless of ambient conditions.

Supports both Celsius and Fahrenheit. Works across all flour types including whole wheat, rye, spelt, and einkorn. Starter activity input lets you calibrate for your specific culture's behavior.

PROFESSIONAL & HOME BAKERS

Built for bakers who want repeatability and data-driven control over their sourdough process. Used by professional bakery instructors for workshop demonstrations and planning.

No login required. Works offline once loaded.

FREE VERSION

This is the free edition of S.D TIMER, supported by banner ads. For an ad-free experience, upgrade to S.D TIMER Pro.