Schedules
Sourdough Fermentation Temperature vs. Time Chart
A practical chart of bulk and proof times across kitchen temperatures. Use this to schedule any sourdough.
Short answer: sourdough bulk takes 4 hours at 80°F, 5 hours at 75°F, 7 hours at 70°F, and 10+ hours at 65°F. Below 60°F, fermentation effectively stops. Use this chart to plan around your kitchen temperature.
The temperature-time relationship
Fermentation rate roughly doubles for every 10°F increase in temperature, within the active range (60–95°F).
This means:
- 80°F dough is twice as fast as 70°F dough
- 90°F dough is fast (4x of 70°F) but yeast is stressed at 95°F+
Most home kitchens are 65–78°F.
Bulk fermentation chart
For a standard 75% hydration dough at peak starter activity:
| Dough temperature | Bulk time (to 50–60% rise) |
|---|---|
| 65°F | 10–12 hours |
| 68°F | 8–10 hours |
| 70°F | 7–9 hours |
| 72°F | 6–8 hours |
| 75°F | 5–6 hours |
| 78°F | 4–5 hours |
| 80°F | 3.5–4.5 hours |
| 82°F | 3–4 hours |
| 85°F | 2.5–3 hours |
Use as a guideline. Visual signs (rise %, jiggle, dome) override clock time.
Final proof chart
After shaping:
| Dough temperature | Final proof time |
|---|---|
| 65°F | 4–6 hours (or refrigerate) |
| 70°F | 2.5–3 hours |
| 75°F | 1.5–2 hours |
| 78°F | 1–1.5 hours |
| 80°F | 45 min – 1 hour |
Watch for the finger-dent test. Proof time is shorter than bulk because gluten is now developed.
Cold retard times
Cold retard slows but doesn't stop fermentation:
| Fridge temp | Equivalent room-temp progress |
|---|---|
| 35°F | Almost stopped (1 hour cold ≈ 5 min at room) |
| 40°F | Slow (1 hour cold ≈ 12 min at room) |
| 45°F | Moderate (1 hour cold ≈ 20 min at room) |
| 50°F | Fast cold (1 hour cold ≈ 30 min at room) |
Most home fridges are 38–42°F. A 12-hour retard at 40°F adds about 2.5 hours of equivalent room-temp fermentation.
How to know your kitchen temperature
Use a kitchen thermometer:
- Place near where dough will sit
- Read after 20 min
- Note the time of day
Most kitchens vary 10°F across the day:
- Morning (cool): 68°F
- Midday (warm): 75°F
- Evening (peak warm): 78°F
Plan based on the average over the bulk period.
Dough temperature vs. ambient
The dough takes time to equilibrate to ambient. After mixing:
- Use warm water (90°F) → dough at 78°F immediately
- Use room-temp water (75°F) → dough at 75°F
- Use cold water (60°F) → dough at 70°F (cold-mass effect)
The water temperature you choose sets the starting dough temperature.
A "desired dough temperature" formula
Some bakers calculate water temperature for a target dough temp:
Target water = (3 × Target dough) − (Flour + Air + Friction + Starter temps)
For target dough 76°F at room temp 72°F:
- 3 × 76 = 228
- Subtract flour (72) + air (72) + friction (4) + starter (75) = 223
- Target water = 228 - 223 = 5? No, this calculator is for stand-mixer use
For most home bakers:
- Cool kitchen → use 90°F water
- Warm kitchen → use 75°F water
- Hot kitchen → use 65°F water
This rough rule produces 75–78°F dough.
A real example
Bake on a 72°F day:
- Mix at 9 AM with 90°F water (dough hits 78°F)
- Bulk 4–5 hours (ready by 1–2 PM)
- Shape at 2 PM
- Final proof 1.5 hours (ready by 3:30 PM)
- Bake at 4 PM
- Slice by 6 PM
Same recipe at 65°F:
- Mix at 9 AM with 95°F water (dough at 72°F)
- Bulk 7–9 hours (ready by 4–6 PM)
- Shape at 6 PM
- Cold retard overnight, bake morning
The schedule shifts dramatically.
Faster fermentation with warmer dough
To speed up bulk:
- Use warmer water
- Place dough in warm spot (oven with light, top of fridge, proofing box)
- Kitchen aim 78–82°F
To slow down fermentation:
- Use cooler water
- Place dough in cool spot
- Refrigerate
A summer warning
In summer, kitchens can hit 85°F:
- Bulk 2.5 hours
- Proof 45 min
- Easy to over-ferment
Strategies:
- Use ice water in the dough
- Refrigerate dough mid-bulk
- Cold retard early
A winter strategy
In winter, kitchens may be 65°F:
- Bulk 10+ hours (overnight)
- Proof 4 hours
Strategies:
- Use very warm water (95°F)
- Use proofing box (78°F)
- Plan longer schedules
- Embrace cold retard
Why visual signs matter more than clock
Clock times are guidelines:
- Your starter strength varies
- Your specific flour ferments differently
- Your kitchen temperature isn't always the same
Visual signs are universal:
- 50–60% rise from initial mix
- Dough has jiggle when shaken
- Dome shape on top
- Slight bubbles visible
When you see these signs, the dough is ready — regardless of the clock.
A printable chart
For your kitchen wall, copy this:
At 75°F:
- Bulk: 5 hours
- Proof: 1.5 hours
- Total: 7 hours
At 78°F:
- Bulk: 4 hours
- Proof: 1 hour
- Total: 5.5 hours
At 70°F:
- Bulk: 7 hours
- Proof: 2.5 hours
- Total: 10 hours
Cold retard:
- 12 hours at 40°F = ~3 extra hours of fermentation
A starter-strength caveat
These times assume a vigorous starter. If your starter is sluggish:
- Add 30–60 min to all times
- Or refresh the starter twice before mixing
A weak starter slows everything.
A high-altitude note
At high altitude:
- Lower air pressure
- Dough rises faster (less resistance)
- Reduce bulk time by 20%
The same recipe in Denver bulks faster than at sea level.
A practical takeaway
For each bake, log:
- Mix time
- Dough temperature (right after mix)
- Bulk start
- Bulk end (visual signs)
- Final proof time
- Bake time
After 5 bakes, you'll know your kitchen-specific timings. The chart is a starting point; your data is the final word.
A final note
Temperature is the single biggest variable in sourdough timing.
Once you understand the temperature-time relationship, you can:
- Bake in any season
- Adjust on the fly
- Plan around your schedule
- Develop new recipes
The chart above is a tool, not a rule. Use it as a starting point, then refine based on your kitchen.