The Ultimate Sourdough Bulk Fermentation Chart (Time vs. Temperature)

Quick Answer:

At 75°F (24°C), bulk fermentation takes 4–6 hours at a 30–50% rise. At 65°F allow 8–12 hours and 75–100% rise. At 80°F shape at 25–30% rise after 3–4 hours. Jump to Full Chart ↓

For a full breakdown of timing by temperature, see our dedicated guide on how long bulk fermentation takes.

Knowing when bulk fermentation is actually done is a skill in itself — and it has nothing to do with the clock. Your dough gives you 6 clear signals when it’s ready to shape.

📋 Read the Dough: Learn to spot the jiggle, the dome, the bubbles, and the pull test. Full visual breakdown here: 7 Signs Bulk Fermentation Is Done →

What Is Bulk Fermentation?

Bulk fermentation — also called the bulk rise or first rise — is the stage that begins the moment you add your starter to the flour and water. It ends when you tip the dough out to pre-shape. Everything that happens in between is bulk fermentation.

During this period three things happen simultaneously:

• Wild yeast produces CO₂, inflating the dough and creating an open, airy crumb
• Lactic acid bacteria produce acids that develop the complex sour flavor and strengthen gluten
• Enzymes break down starches into sugars that the yeast and bacteria feed on

This is the most important stage in sourdough baking. Get it right and the rest follows. Get it wrong and no amount of good shaping or baking technique can rescue the loaf. Dense bread, gummy crumb, flat loaves, and poor oven spring are almost always caused by bulk fermentation that went too short or too long.

Cold bulk fermentation is one of the most misunderstood techniques in sourdough — and it’s completely different from cold proofing. If you’ve ever put unshaped dough in the fridge overnight and wondered what to do next, this is for you.

🧊 Baking Tomorrow? Learn how cold bulk works, how much rise to target before refrigerating, and how to shape cold dough: Cold Bulk Fermentation Guide →

Sourdough Bulk Fermentation Temperature Chart

This is the core bulk fermentation chart every sourdough baker needs. It maps dough temperature to fermentation time and target rise percentage so you know the ideal moment to shape.

Dough Temp	Est. Bulk Time	Target Rise Before Shaping	What to Look For
65°F (18°C)	8–12 Hours	75% – 100% Rise	Doubled in size, domed surface, bubbles throughout
70°F (21°C)	6–9 Hours	50% – 75% Rise	Significant growth, jiggly when moved, bubbles on sides
75°F (24°C)	4–6 Hours	30% – 50% Rise	Puffy and domed, passes windowpane test
80°F (27°C)	3–4 Hours	25% – 30% Rise	Slight growth, many bubbles visible, dough feels airy
85°F (29°C)	2–3 Hours	20% – 25% Rise	Move fast — fermentation is aggressive at this temp

Why Warmer Dough Needs Less Rise

One of the biggest mistakes beginners make is focusing only on time instead of temperature and percentage rise. The reason is Thermal Momentum.

Warm dough ferments faster and retains heat longer. Even after shaping and placing the dough into the refrigerator for cold proofing, fermentation continues aggressively for several hours while the core of the dough cools down.

• Cool dough (65°F): Must rise more (75–100%) to build enough gas and structure because it stops fermenting almost immediately once it hits the cold air of the fridge.
• Moderate dough (70–75°F): Usually needs a 40–60% rise before shaping to achieve a balanced crumb.
• Warm dough (80°F): Only needs a 25–30% rise because it will continue to expand significantly as it slowly cools in the refrigerator.

Why your dough feels “Sticky” vs. “Hydrated”: Many bakers confuse high hydration with over-fermentation. If your dough was easy to handle during stretch and folds but became a sticky, unmanageable mess by the end of bulk, you didn’t add too much water—you waited too long. The Protease enzyme has begun eating your gluten. If this happens, reduce your rise target by 10% on your next bake.

Stopping bulk fermentation earlier at higher temperatures prevents overproofing and gluten breakdown, which causes loaves to bake flat.

Bulk Fermentation Chart by Starter Percentage

The amount of starter in your recipe directly controls how fast bulk fermentation moves. This chart assumes a dough temperature of 75°F (24°C). Adjust time up or down based on the temperature chart above.

Starter %	Est. Bulk Time at 75°F	Notes
5%	8–12 hours	Very slow — used for overnight room temp bulk fermentation
10%	6–8 hours	Standard for most long fermentation recipes
20%	4–6 hours	Most common ratio — reliable and predictable
25%	3–5 hours	Faster — good for same-day bakes
30%+	2–4 hours	Very fast — monitor closely to avoid overfermentation

If your bulk fermentation is consistently taking longer than these ranges, the problem is likely your starter rather than your technique. A starter that isn’t rising properly won’t drive bulk fermentation efficiently regardless of temperature.

Bulk Fermentation Chart by Flour Type

Different flours ferment at dramatically different speeds due to their mineral content and enzyme activity. This chart shows how flour type modifies your bulk fermentation timing at 75°F with 20% starter.

Flour Type	Speed vs. White Flour	Adjusted Bulk Time	Notes
White bread flour	Baseline	4–6 hours	Predictable, forgiving, most recipes are calibrated to this
All-purpose flour	Slightly slower	5–7 hours	Lower protein = slightly slower fermentation
Whole wheat (10–20%)	20–30% faster	3–5 hours	Bran feeds bacteria; watch carefully after 3 hours
Whole wheat (50%+)	40–50% faster	2–4 hours	Aggressive fermentation — use cooler water or less starter
Rye (10–20%)	30–40% faster	2.5–4 hours	Even small amounts of rye accelerate fermentation significantly
Spelt	Slightly faster	3.5–5 hours	More extensible gluten — don’t over-ferment or it collapses
Einkorn	Faster + fragile	2–3.5 hours	Very weak gluten — stop bulk earlier than you think

Seasonal Bulk Fermentation Adjustment Chart

Your kitchen temperature changes with the seasons, which means your bulk fermentation timing changes too — even if you follow the same recipe exactly. This chart gives you a quick seasonal reference.

Season / Kitchen Condition	Typical Dough Temp	Bulk Time Adjustment	Key Strategy
Summer (hot kitchen, 80°F+)	78–85°F	30–50% shorter	Use cold water; shape at 20–25% rise; bake sooner
Spring / Fall (ideal, 68–72°F)	72–76°F	Standard chart times	Follow the temperature chart above directly
Winter (cool kitchen, 62–68°F)	65–70°F	30–50% longer	Use warm water; proof in oven with light on; allow full rise
Very cold kitchen (below 62°F)	Below 65°F	Up to 2x longer	Consider overnight bulk at room temp with reduced starter (5–10%)

If your sourdough consistently fails in winter, the issue is almost always bulk fermentation being cut short because the kitchen is too cold. Our guide on sourdough not rising in winter covers this in detail.

Desired Dough Temperature (DDT): How to Hit Your Target Every Time

The charts above tell you what to do once you have a dough temperature — but how do you control that temperature before mixing? That is what Desired Dough Temperature (DDT) is for. DDT is the professional baker’s method for calculating the exact water temperature needed to hit your target dough temperature every single bake, regardless of your flour temperature or room temperature.

Using DDT before every bake means you arrive at bulk fermentation already knowing exactly where on the temperature chart you are — rather than measuring your dough and hoping it landed in a useful range. For a deeper dive into how dough temperature affects every stage of fermentation, see our guide on how dough temperature affects fermentation.

Stretch and Folds During Bulk Fermentation

Stretch and folds happen during bulk fermentation — they are not a separate step. The moment you add your starter to the dough, bulk fermentation begins, and stretch and fold sets strengthen the gluten network while fermentation is actively progressing.

A standard schedule at 75°F with 20% starter looks like this:

Time Into Bulk	Action	Notes
0 min	Mix starter in, begin bulk fermentation	Cover and rest
30 min	Set 1: 4 stretch and folds	Rotate bowl 90° between each fold
60 min	Set 2: 4 stretch and folds	Dough should feel more elastic
90 min	Set 3: 4 stretch and folds	Dough tightening noticeably
120 min	Set 4 (optional): 4 stretch and folds	Skip if dough is already taut and smooth
120–360 min	Rest undisturbed	Monitor rise percentage until target is reached

After the folding sets are complete, do not disturb the dough. Touching or folding it again can deflate the gas bubbles that have been building. At warmer temperatures (80°F+), reduce to 2–3 sets and shorten rest intervals to 20 minutes to avoid over-developing in the early stage. For a deeper breakdown of technique, see our stretch and fold schedule for beginners.

The Windowpane Test: What It Does (and Doesn’t) Tell You

The windowpane test is widely misunderstood as a way to confirm bulk fermentation is done. It is not. It measures one thing only: gluten development.

To perform the test, take a small piece of dough and stretch it slowly between your fingers. If it stretches thin enough to let light through without tearing, gluten development is sufficient. If it tears immediately, the gluten network needs more time or more folds.

What the Windowpane Test Tells You	What It Does NOT Tell You
Gluten is strong enough to trap gas	Whether fermentation is complete
Dough is ready for shaping (structurally)	Whether rise % target has been reached
Folding sets have been effective	Whether dough is underproofed or overproofed

A dough can pass the windowpane test perfectly at hour two and still need another three or four hours of bulk fermentation. These are independent measurements. Always use the temperature chart and rise percentage as your primary guide — the windowpane test is a secondary confirmation of gluten strength, not a signal to stop.

Best Container for Bulk Fermentation (And How to Size It)

The right container makes measuring percentage rise accurate — and that accuracy is what the chart above depends on. The two most important qualities are straight walls and milliliter markings.

The container you use during bulk fermentation matters more than most bakers realize. You need to be able to see the rise, measure it accurately, and hold a consistent temperature throughout the process. A clear, straight-sided container with volume markings does all three. A ceramic bowl does none.

For a full breakdown of which containers actually work — glass vs. plastic, which sizes to use, and the exact picks serious home bakers rely on — see our guide: Best Bulk Fermentation Container for Sourdough

Bowls and irregular containers make it nearly impossible to visually track rise percentage accurately. A straight-walled container with markings lets you track the exact rise at a glance without disturbing the dough.

Container Type	Accuracy	Notes
Straight-walled tub with ml markings	Best	Cambro or similar deli containers are ideal
Straight-walled tub without markings	Good	Add your own rubber band at start, another at target %
Wide ceramic or glass bowl	Poor	Volume hard to judge accurately due to curved walls
Mixing bowl (no markings)	Unreliable	Eyeballing % rise in a bowl is nearly impossible

How to size your container: Multiply your recipe’s total flour weight in grams by 1.5 — this gives the approximate starting volume in milliliters of your mixed dough. Then choose a container with at least double that capacity to allow room for the full rise without overflow. For example, a 1,000g flour recipe starts at roughly 1,500ml, so you need a container that holds at least 3,000ml.

If you don’t have a straight-walled container with markings, use the aliquot jar method in a small straight-sided jar alongside your main dough. It gives the same precision without needing to upgrade your primary vessel.

The Aliquot Jar Method (Tracking Bulk Fermentation)

Many experienced bakers use an aliquot jar to track the exact percentage rise of sourdough dough during bulk fermentation without disturbing the main batch. See our full aliquot jar guide for a step-by-step walkthrough with photos.

1. Take a Sample: Immediately after mixing, place a small 20g piece of dough into a small, straight-sided jar.
2. Mark the Start: Use a rubber band or marker to indicate the starting level of the dough.
3. Watch the Rise: Because the sample ferments at the same rate as the main dough, it acts as a “gas gauge.” When the aliquot jar shows the Target Rise % from the chart above, your main batch is ready to shape.

Using an aliquot jar helps bakers avoid both underproofed and overproofed sourdough by providing a clear visual indicator of fermentation progress that doesn’t require guessing from the main dough.

How to Know When Bulk Fermentation Is Done: 6 Signs

Beyond the chart, your dough will tell you when it’s ready. Check for all of these signs together — one sign alone is not reliable enough to call it done.

Sign	What It Looks Like	What It Means
Volume increase	Dough has risen 30–100% depending on temp (see chart)	Yeast has produced enough CO₂ gas
Domed surface	Top of dough is rounded, not flat or sunken	Active fermentation still present — good timing
Bubbles on sides	Small bubbles visible through the bowl sides	Fermentation is active throughout the dough mass
Jiggle test	Dough wobbles like set jello when you shake the bowl	Gluten is developed and gas is trapped — not stiff, not sloshing
Passes windowpane test	Small piece stretches thin without tearing	Gluten development is sufficient for shaping
Smooth surface	Dough top looks smooth, not shaggy or wet	Gluten network has organized properly

The jiggle test explained: Gently shake the bowl side to side. Properly fermented dough wobbles as one cohesive mass — like set jello. Underfermented dough feels stiff and barely moves. Overfermented dough sloshes and feels liquid, with the surface rippling independently of the mass underneath. The jiggle test is one of the fastest and most reliable checks you can do without disturbing the dough.

How long is too long for bulk fermentation?

Bulk fermentation is “too long” when the dough begins to lose its ability to hold tension. Visually, this looks like the surface going from domed and taut to flat or pitted. If the dough smells sharply of alcohol or tears when you try to pre-shape it, you have exceeded the bulk fermentation window. At 75°F (24°C), this usually happens after the 7-hour mark. Signs bulk fermentation has gone too far:

• Dough surface looks flat or has started to collapse inward
• Large, irregular bubbles on the surface (not small, even ones)
• Dough feels slack, sticky, and won’t hold tension when you try to shape it
• Strong alcohol or acetone smell — a sign the yeast has exhausted available sugars

How to Stop Overproofing Before It Happens: A Pre-Bake Checklist

Overproofing during bulk fermentation is the most common — and most damaging — mistake in sourdough. The good news is that it’s almost entirely preventable with a few habits in place before you even start mixing.

• Measure your dough temperature immediately after mixing. Don’t rely on room temperature. Use an instant-read thermometer and find the correct target rise % from the chart above before bulk even starts.
• Set up your aliquot jar at the beginning. Don’t try to assess rise percentage from the main bowl by eye — it’s too easy to misjudge. The aliquot jar gives you an objective read.
• Set a timer for 30-minute check-ins. During the second half of bulk, fermentation accelerates. Dough that was 20% risen can reach 50% in under an hour at 78°F. Don’t leave it unattended.
• Stop before the dough looks “obviously ready.” If the dough looks exactly as done as you expect, you may already be 20–30 minutes past the ideal window. Especially at warmer temperatures, shape slightly earlier than feels natural.
• Know all 7 readiness signs. Volume rise is the most objective measure, but the dome, jiggle, bubbles, and surface texture all matter too. See our full guide on signs bulk fermentation is done for the complete checklist.
• Never use the oven proof setting. Most oven proof settings run at 100–110°F — far too hot. Use the oven with just the light on (typically 75–80°F) or a dedicated proofing box.
• Use cooler water in summer. If your kitchen is above 75°F, use cold or ice water when mixing to bring your initial dough temperature down to the 72–75°F range.

Same-Day vs. Overnight Bulk Fermentation

Bulk fermentation can be done either at room temperature (same-day) or overnight in the refrigerator. Each approach produces different results and suits different schedules.

	Same-Day Bulk (Room Temp)	Overnight Bulk (Fridge)
Temperature	68–80°F	38–40°F
Time	3–8 hours	8–16 hours
Starter %	15–25%	5–10%
Flavor	Milder, less sour	More complex, tangier
Schedule	Mix in morning, bake same evening	Mix at night, shape and bake next day
Risk	Easy to over-ferment if kitchen is warm	Less forgiving if under-developed before fridge

Important note on overnight bulk fermentation: If you choose to bulk ferment in the fridge overnight, use a significantly lower starter percentage (5–10%) and make sure your dough has at least 20–30 minutes of active fermentation at room temperature before going into the cold. Putting dough straight into the fridge with 20% starter will result in very little fermentation activity overnight.

Factors That Influence the Chart

While temperature is the primary driver of bulk fermentation timing, other variables can shift your results significantly:

• Starter Strength: If your sourdough starter smells like acetone, the yeast may be weakened, and fermentation will take much longer than the chart predicts.
• Flour Type: Whole wheat and rye flours contain more minerals and ferment significantly faster than white bread flour (see flour chart above).
• Inclusions: Adding sugar or fats (brioche) slows fermentation, while honey or fruit can accelerate it.
• Starter Ratio: A recipe using 20% starter will move faster than one using only 10% starter (see starter percentage chart above).
• Hydration: Higher hydration doughs (80%+) ferment slightly faster than stiffer doughs because water acts as a medium for yeast and bacterial activity. See our sourdough hydration guide for how to adjust water levels to control fermentation speed.
• Salt: Salt slows fermentation. Make sure salt is properly incorporated — pockets of salt against the starter can kill yeast locally and cause uneven fermentation.
• Autolyse: If you use an autolyse step before adding your starter, the dough begins enzymatic activity earlier — factor this into your total bulk time.

Bulk Fermentation vs. Proofing: What’s the Difference?

Bulk fermentation and proofing are two separate fermentation stages and they serve different purposes. Confusing them is one of the most common reasons sourdough fails.

	Bulk Fermentation	Final Proof (Cold Proof)
When	After mixing, before shaping	After shaping, before baking
Purpose	Build flavor, develop gluten, create gas	Final rise, improve flavor, firm up for scoring
Temperature	Room temperature (65–80°F)	Refrigerator (37–40°F)
Duration	3–12 hours depending on temp	12–48 hours
Can you skip it?	No — bulk fermentation is essential	Optional, but highly recommended

For a complete guide to the cold proofing stage that follows bulk fermentation, see our guide on how long you can cold proof sourdough.

Frequently Asked Questions

---

The Protease Rule: Why Overproofing Destroys Dough

The charts above tell you when to stop bulk fermentation. This section tells you why the timing matters so much — and what actually goes wrong when you push too far.

During bulk fermentation, lactic acid bacteria produce organic acids that build flavor. But those same acids gradually stimulate a naturally occurring enzyme called protease. Protease literally eats gluten — it breaks down the protein network responsible for trapping gas and holding the dough’s structure.

At normal fermentation temperatures (65–78°F), protease activity is slow and manageable. But as dough temperature approaches 90°F (32°C), protease becomes hyperactive. Gluten degrades rapidly. The dough goes from perfect to unsalvageable in a matter of 30–60 minutes — and no amount of shaping technique will fix it.

This is the real reason the chart says to shape warmer dough at a lower percentage rise. It’s not just about thermal momentum — it’s about getting the dough into the fridge before protease has time to destroy the gluten structure you’ve spent hours building.

The practical rule: Never let dough temperature exceed 85°F during bulk fermentation. Above that, check every 20 minutes. Above 90°F, shape immediately regardless of rise percentage.

---

Does Sourdough Need to Double During Bulk Fermentation?

No — and this is one of the most damaging myths in sourdough baking.

Many beginner recipes say “wait for your dough to double.” This is the single most common reason people over-ferment and end up with flat, sticky, unshapeable dough. The target rise depends entirely on dough temperature — and at warmer temperatures, waiting for a full double will always produce an overproofed loaf.

• At 65°F: Doubling (100% rise) is appropriate and expected.
• At 75°F: Shape at 30–50% rise — well before doubling.
• At 80°F: Shape at 25–30% rise. Waiting to double will almost certainly destroy the loaf.

Use the temperature chart at the top of this guide as your reference, not the “did it double?” visual check. The aliquot jar method makes this exact measurement simple without disturbing your main dough.

---

High Altitude Bulk Fermentation Adjustments

If you bake above 3,000 feet, the charts above will consistently produce overfermented dough — and you may not understand why until you know about altitude’s effect on fermentation.

At high altitude, lower atmospheric pressure allows the gases produced by yeast to expand faster than they do at sea level. The yeast activity itself isn’t faster, but the physical expansion of CO2 in the dough is accelerated. The result: your dough appears more risen than it actually is fermented — and if you’re using rise percentage as your guide, you’ll overshoot.

Altitude	Bulk Time Adjustment	Key Strategies
Sea level – 2,000 ft	Use chart as written	Standard chart applies
2,000 – 4,000 ft	10–15% shorter bulk	Watch dough closely after 75% of estimated time
4,000 – 6,000 ft	20–30% shorter bulk	Reduce starter to 15%; shape earlier than you think
Above 6,000 ft	30–40% shorter bulk	Use cooler water; reduce starter to 10%; monitor every 30 min

Additional high altitude adjustments: Reduce hydration slightly (lower air pressure causes flour to absorb water faster, making high-hydration doughs harder to handle). Use a lower starter percentage to slow fermentation enough to control it. And always use the aliquot jar — visual assessment of the main dough mass is even less reliable at altitude because gas expansion is uneven.

If your bulk fermentation is consistently running long, see our troubleshooting guide: why is my bulk fermentation so slow?

---

What to Do If You’ve Over-Fermented Your Dough

If your bulk fermentation has gone too far, your options depend on how overproofed the dough is. See our full guide on how to fix overproofed sourdough for step-by-step recovery options, but here is the quick triage:

• Slightly over-fermented (dough is soft but still holds some shape): Shape immediately and cold proof for the minimum time (8–12 hours). Bake straight from the fridge. The loaf will be denser than ideal but still edible.
• Moderately over-fermented (dough is slack and sticky, holds shape poorly): Shape into a loaf pan rather than a freestanding boule. The sides of the pan will support the structure the gluten can no longer provide. Bake immediately without a cold proof.
• Severely over-fermented (dough collapses and won’t hold any shape): Don’t try to bake it as bread. Spread it on an oiled sheet pan, dimple it all over, add flaky salt and olive oil, and bake as focaccia at 450°F for 20–25 minutes. See our guide on overproofed sourdough focaccia for the full rescue method.
• Went past your window? See our guide on what happens if bulk fermentation goes too long — including how to tell how bad it is and what you can still do.

The most important rule: once dough is over-fermented, more time will only make it worse. Act immediately.

---

Related Sourdough Guides

Understanding bulk fermentation works best alongside these related guides:

• Bulk fermentation vs proofing — understand the difference between these two essential stages
• How long does bulk fermentation take — exact time guide by dough temperature so you never guess again
• How long can you cold proof sourdough — what happens after bulk fermentation is complete
• Underproofed vs overproofed sourdough — how to diagnose and fix fermentation problems
• How to use an aliquot jar — the most accurate way to track bulk fermentation rise
• Stretch and fold schedule for beginners — timing and technique during bulk
• Sourdough proofing time chart — the companion chart for the cold proofing stage
• How to fix overproofed sourdough — rescue methods when bulk goes too far
• Sourdough not rising in winter — seasonal adjustments when your kitchen is cold
• Best final proof temperature for sourdough — temperature guide for the proofing stage after shaping
• How dough temperature affects fermentation — deep dive into desired dough temperature
• Cold ferment sourdough — how to bulk ferment overnight in the fridge
• Fermentation guide — complete overview of sourdough fermentation
• Signs bulk fermentation is done — 7 visual cues to look for before you shape

Final Thoughts

A sourdough bulk fermentation chart is only as useful as your ability to read your dough alongside it. Temperature and percentage rise are your two primary guides — time is just a rough estimate that changes with every variable in your kitchen.

For bakers who want to fit sourdough into a busy schedule, see our complete guide to overnight bulk fermentation — including the right starter percentage and whether to use the counter or fridge.

Use the charts above as your starting framework, track your dough with an aliquot jar, and pay attention to the visual signs. After a few bakes, you will stop needing the chart entirely because you will know what your dough looks and feels like when it is ready.

After bulk fermentation, the dough usually enters the refrigerator for the final rise. See our full guide on how long you can cold proof sourdough to understand how cold fermentation affects flavor and structure.