Sourdough Starter Feeding Schedule by Temperature
Why Kitchen Temperature Is the Most Important Variable in Sourdough
TL;DR: Your sourdough starter feeding schedule is determined almost entirely by your kitchen temperature. The ideal range is 75–80°F (24–27°C). Below 65°F, fermentation crawls. Above 85°F, bacteria outpace yeast and the starter turns too acidic. The schedule you read online was written for someone else's kitchen.
In our testing across thousands of customer activations, cold kitchens cause more starter failures than any other single factor — more than flour type, more than water quality, more than feeding ratios. In January, we hear from bakers in unheated houses who have been feeding their starter for 14 days with nothing to show for it. Move it somewhere warm and it doubles within 8 hours.
Temperature isn't just about speed. It changes the entire flavor profile of your bread. Cold, slow fermentation produces more acetic acid — that sharp, punchy sour you get in San Francisco sourdough. Warm, fast fermentation produces more lactic acid — mild, yogurt-like sourness. Same starter, same flour, completely different bread depending on where you keep that jar.
Temperature Quick Reference
| Temperature | Feed Every | Rise Time |
|---|---|---|
| Below 65°F (18°C) | 24 hrs | 18–24+ hrs |
| 65–70°F (18–21°C) | 16–20 hrs | 12–16 hrs |
| 70–75°F (21–24°C) | 12–16 hrs | 8–12 hrs |
| 75–80°F (24–27°C) ✅ | 8–12 hrs | 4–8 hrs |
| 80–85°F (27–29°C) | 6–8 hrs | 3–5 hrs |
| Above 85°F (29°C+) | 4–6 hrs or fridge | 2–4 hrs |
How to Find Your Kitchen's True Temperature
Don't trust your wall thermostat. The spot where you set your jar can be 5–10 degrees different from the room's average — cooler near a window in winter, warmer near the stove or on top of the fridge. Use a $10 instant-read thermometer and check the actual air temperature right next to your jar. That number is what matters.
For the full feeding walkthrough including what to do when things go sideways, see our sourdough starter feeding guide. For temperature-specific troubleshooting, our temperature control guide covers every scenario from January cold snaps to August heat waves.
Ready to start? The Mother is a 288-year-old live culture — free with postage. Once you know your kitchen temperature, you'll know exactly how to care for her from day one.