Bulk Fermentation Timing Guide (Sourdough): How Long It Takes How to Know When It’s Done

Bulk fermentation is the stage after mixing when sourdough dough ferments, strengthens, and develops flavor.
It’s also the most common failure point in sourdough baking—because the clock lies.

There is no universal “4-hour” or “8-hour” bulk.

Correct bulk fermentation depends on:

• Dough temperature
• Starter (levain) strength
• Inoculation (how much starter you used)
• Flour type and hydration
• Your fermentation environment

The real goal isn’t time.
The goal is proper fermentation.

In this guide, you’ll learn:

• Reliable bulk fermentation time ranges
• A temperature-based bulk fermentation chart
• Clear visual and tactile signs bulk is finished
• Fixes for under- and over-fermented dough
• A simple method to dial in bulk timing in 1–2 bakes

What Is Bulk Fermentation?

Bulk fermentation begins once the dough is fully mixed (or after autolyse, depending on method) and ends when the dough is divided and shaped.

During bulk fermentation, three processes happen at once:

1. Fermentation – yeast and bacteria produce CO₂ and organic acids
2. Strength development – gluten strengthens through time and folds
3. Flavor building – acids and byproducts create complexity

You should end bulk fermentation when the dough has:

• Enough gas (visible rise and bubbles)
• Enough strength (smooth, elastic, cohesive)
• Enough fermentation (puffy and airy, not collapsing)

Dough Temperature Matters More Than Room Temperature

Bulk fermentation tracks best with dough temperature, not the thermostat.

• Warm dough ferments faster
• Cool dough ferments slower

Typical target dough temperature (TDT):

• Same-day bakes: 76–80°F (24–27°C)
• Cooler dough (70–74°F / 21–23°C) will take significantly longer

Tip: Measure dough temperature right after mixing and again mid-bulk with a probe thermometer.

Bulk Fermentation Timing Chart (Most Common Setup)

Assumptions for this chart:

• Inoculation: ~20% levain (100g levain per 500g flour)
• Hydration: ~70–78%
• Flour: bread flour / AP with some whole grain
• Starter is active and predictable

If your starter is weak, these times can be off by hours.

Bulk Fermentation Time by Dough Temperature

Dough Temperature	Expected Bulk Time	Notes
82°F / 28°C	3–5 hours	Very fast; easy to over-ferment
78–80°F / 26–27°C	4–6 hours	Ideal for same-day bakes
75–77°F / 24–25°C	5–7 hours	Common kitchen range
72–74°F / 22–23°C	6–9 hours	Longer bulk, deeper flavor
68–71°F / 20–21°C	8–12 hours	Overnight-style bulk possible

Use this chart to set expectations—finish bulk based on dough signs, not time alone.

How to Know When Bulk Fermentation Is Done

Bulk fermentation is finished when multiple signs align, not just one.

The 7 Most Reliable Signs Bulk Is Complete

1. Volume increase (not always double)
• Typical rise: 30–75%
• Warmer dough needs less visible rise
• Cooler dough often shows more
2. Smoother, domed dough surface
• Transitions from shaggy → cohesive → inflated
3. Visible bubbles
• Blisters on the surface and along container walls
4. Jiggle test
• Dough wobbles like a waterbed, not liquid batter
5. Edges releasing from the container
• Dough slightly pulls away as it inflates
6. Lighter feel during folds
• Early folds feel dense; later folds feel buoyant
7. “Puffy but resilient” texture
• Gently pressed dough feels airy and elastic, not fragile

Rule of thumb:

• Tight, heavy, dense dough → keep bulking
• Very gassy, weak, spreading dough → bulk went too far

Rise Targets That Work Better Than “Doubling”

Instead of chasing “double,” use temperature-based rise targets:

• Warm dough (78–82°F / 26–28°C): 30–50% rise
• Moderate (74–77°F / 23–25°C): 50–70% rise
• Cool (68–73°F / 20–23°C): 70–100% rise

Warm dough ferments faster internally and can over-ferment long before it looks large.

Bulk Fermentation Sample Schedules

Same-Day Bake (Warm Dough)

• Dough temp: 78–80°F (26–27°C)
• Bulk: 4–6 hours
• Folds: 3–5 sets in first 2 hours
• End bulk: ~40–60% rise + bubbles + jiggle

Typical Kitchen Schedule

• Dough temp: 74–76°F (23–24°C)
• Bulk: 5–7 hours
• Folds: 3–4 sets
• End bulk: ~60–70% rise + wobble

Cool / Overnight-Style Bulk

• Dough temp: 68–72°F (20–22°C)
• Bulk: 8–12 hours
• Folds: 2–3 early sets
• Watch carefully if starter is strong

How Starter Strength Affects Bulk Fermentation

Starter strength can shorten or lengthen bulk by hours.

A healthy starter should:

• Rise and peak predictably after feeding
• Smell mildly tangy and yeasty
• Show even aeration throughout

Weak starters cause long bulks, dense crumbs, and inconsistent results.

Common Bulk Fermentation Problems (and Fixes)

Under-Fermented Dough

Signs

• Tight, heavy dough
• Few bubbles
• Dense or gummy crumb

Fix

• Extend bulk 30–90 minutes
• Increase dough temperature
• Use levain closer to peak

Over-Fermented Dough

Signs

• Very gassy but weak dough
• Spreads and tears during shaping
• Flat loaf with tunnels

Fix

• End bulk earlier
• Reduce inoculation
• Keep dough cooler
• Build strength early

Best Tools for Bulk Fermentation Timing

You don’t need fancy equipment:

• Straight-sided container
• Rubber band or marker
• Probe thermometer
• Notebook for logging time, temp, and rise

After a few bakes, you’ll know your house timing.

Bulk Fermentation Cheat Sheet

• Warm dough: Stop at 30–50% rise
• Moderate dough: Stop at 50–70% rise
• Cool dough: Stop at 70–100% rise

Always confirm with jiggle, bubbles, and dough feel.

Bulk Fermentation FAQ

Should bulk fermentation double?
Not usually. Doubling often leads to over-fermentation, especially in warm dough.

Does bulk include stretch and folds?
Yes. Bulk is everything from mix to shaping.

Can I bulk ferment in the fridge?
Cold bulk is possible but harder to control. Most bakers prefer room-temperature bulk with a cold proof.

Why is my dough bubbly but dense after baking?
Common causes are over-fermentation, weak gluten, or under-proofing after shaping.