Sourdough Bulk Fermentation: How Long It Takes at Every Temperature
How this guide was made: it is a researched guide compiled from the published sources listed at the end of this page. We compare what those sources say and do the arithmetic; we don't claim to have baked these loaves. Each instruction is attributed so you can check it.
Bulk fermentation is the long rise between mixing the dough and shaping it. It is also the step that most often goes wrong, because recipes give a time ("4 hours") that only holds at one temperature. This guide puts the published times side by side, shows why they differ, and gives you a calculator for the one thing you can control on the day: the temperature of your mixing water.
Quick answers
- What it is: the first rise, from the end of mixing (or the moment the starter goes in) until you divide or shape the dough [1][6].
- How long: roughly 3–5 hours for a typical recipe with the dough at about 74–78°F [1][2][3]. A cool dough, or one made with very little starter, can need 8–12 hours or more [4][5].
- What controls it: dough temperature first, then the amount and strength of your starter and the flour you use [1][5][7].
- When it's done: judge the dough, not the clock. Look for a smoother, stronger dough that has grown noticeably, jiggles when you shake the bowl, has domed edges and shows bubbles on the top and sides [1][2][3].
What bulk fermentation does
While the dough sits in one mass, the yeasts in your starter make carbon dioxide, which lifts the dough, and the bacteria make organic acids, which add flavour and help condition the gluten [1][2]. The Perfect Loaf warns that cutting this step short tends to give a loaf with weaker flavour and a tighter crumb [1].
Most home recipes also use bulk to build strength. Instead of kneading to full strength at the start, you give the dough a few sets of stretch and folds: lift one side, fold it over, turn the bowl, repeat four times. King Arthur's guide, written by The Perfect Loaf's author, spaces sets about 30 minutes apart, starting 30 minutes into bulk [2]. Each set also evens out the dough's temperature and gives you a chance to see how it is progressing [1][2].
The difference between bulk and proofing is simply timing. Bulk happens while the dough is one big mass; proofing is the final rise after it has been shaped [1].
How long does bulk take? What the sources say
Here are the published figures, each with the conditions it assumes. Notice how much the temperature changes the answer.
| Source | Dough or room temperature | Bulk time | What it assumes |
|---|---|---|---|
| The Perfect Loaf, bulk guide [1] | 74–78°F dough | 2–5 h | A "warm bulk" for most of its recipes |
| King Arthur, "Bulk fermentation, explained" [2] | Room temperature | 3–5 h | A typical sourdough recipe |
| The Perfect Loaf, Beginner's Sourdough [3] | 74–76°F room | About 4 h | That one recipe; its target dough temperature is 78°F |
| The Perfect Loaf, weekday loaf [15] | 75°F dough | About 3.5 h | That one recipe |
| Country Roads Sourdough, same-day loaf [8] | 75°F dough | About 4 h | A recipe that uses extra starter on purpose |
| King Arthur, sourdough schedule [4] | Room temperature | Typically 8–12 h | Recipes with a smaller amount of starter; it tells you to check your recipe |
| Sourdough Archive chart [5] | 65°F dough | 8–12 h | 20% starter (as % of flour) |
| Sourdough Archive chart [5] | 70°F dough | 6–9 h | 20% starter |
| Sourdough Archive chart [5] | 75°F dough | 4–6 h | 20% starter |
| Sourdough Archive chart [5] | 80°F dough | 3–4 h | 20% starter |
| Sourdough Archive chart [5] | 85°F dough | 2–3 h | 20% starter |
| British Sourdough chart [6] | 18–20°C (64–68°F) dough | 12–16 h | Its own recipe; it gives about 9 h at 22°C (72°F) and about 5 h at 26°C (79°F) |
| The Clever Carrot [7] | 80°F (summer) / 68°F (winter) | About 2–4 h / 10–12 h | Its recipe, with about 150 g starter |
Why the numbers don't agree
The sources are not contradicting each other so much as describing different doughs: - Starter amount. More starter means a faster bulk. Sourdough Archive's chart, all at 75°F, runs from 8–12 hours with 5% starter down to 2–4 hours with 30% or more [5]. That is why King Arthur's lower-starter recipes take 8–12 hours [4] while a same-day recipe built around extra starter finishes in about 4 [8]. - Dough temperature versus room temperature. Some figures are for the dough, some for the room. Sourdough Archive points out that two kitchens at the same air temperature can produce doughs 10°F apart, depending on the water used [5]. - Flour. Whole-grain and rye flours speed things up. Sourdough Archive estimates whole wheat at 10–20% of the flour makes bulk 20–30% faster, and rye even more so [5]. Treat those percentages as one site's estimates. - Starter strength. A sluggish starter slows everything. Sourdough Archive suggests checking that your starter reliably doubles within a few hours of a feed before you blame the dough [5]; our starter guide covers what "ready" looks like.
A rule of thumb you'll see: Sourdough Archive says every 10°F drop roughly doubles the bulk time [5]. Its own chart is close to that (4–6 h at 75°F versus 8–12 h at 65°F), but it is one site's simplification, so use it to plan, not to decide when to stop.
Control the temperature: work out your water temperature
You can't easily change the temperature of your kitchen or your flour, but you can change the water. Bakers use the desired dough temperature (DDT) formula for this [9][10][11]:
- Without counting the starter: water = (target dough temperature × 3) − room − flour − friction factor.
- Counting the starter or levain: water = (target × 4) − room − flour − starter − friction factor.
The friction factor is the heat that mixing adds. This is where the sources disagree most:
| Source | Mixing by hand | Stand mixer | Food processor |
|---|---|---|---|
| King Arthur blog [9] | 6–8°F (8 minutes of mixing and kneading) | 22–24°F (its 7-quart mixer method) | — |
| America's Test Kitchen [11] | 5°F | 20°F | 25°F |
| Sourdough Archive [5] | 0°F | 2–4°F on low, 4–6°F on high | — |
Most sourdough is mixed by hand with a short mix and folds, so a hand figure of 0–8°F is the realistic range. Pick one, measure the dough after mixing, and adjust next time.
What target? King Arthur gives 75–78°F as the ideal range for wheat doughs and says the same range suits sourdough [9]. The Perfect Loaf's recipes mostly aim for about 78°F [1]. America's Test Kitchen uses 75°F [11].
Worked examples (target 78°F, starter counted, hand friction 6°F): 1. Cool kitchen: room 68°F, flour 68°F, starter 70°F. Water = 312 − 68 − 68 − 70 − 6 = 100°F. 2. Average kitchen: room 72°F, flour 72°F, starter 74°F. Water = 312 − 72 − 72 − 74 − 6 = 88°F. 3. Warm kitchen: room 82°F, flour 80°F, starter 82°F. Water = 312 − 82 − 80 − 82 − 6 = 62°F.
These line up with The Perfect Loaf's own cheat sheet for its beginner loaf, which calls for much warmer water in a 68°F kitchen than in a 74°F one [3].
Mixing water temperature calculator
Mixing water: —
Formula: water = target × 3 − room − flour − friction, or target × 4 − room − flour − starter − friction when you count the starter. Published friction factors disagree: King Arthur gives 6–8°F for hand mixing and 22–24°F for its stand-mixer method; America's Test Kitchen gives 5°F by hand, 20°F stand mixer, 25°F food processor; Sourdough Archive uses 0°F by hand. In °C, divide a °F friction factor by 1.8. Measure your dough after mixing and adjust next time.
Once the dough is mixed, check it with a probe thermometer. If it came out a couple of degrees off target, you don't need to fix it: just expect bulk to run a little faster (warmer) or slower (cooler) [1].
How to tell when bulk fermentation is done
Every source we reviewed says to end bulk by the dough's condition rather than the hour [1][2][3][5][6]. Combine these signs: 1. Strength: it has gone from shaggy to smooth and elastic, and resists a gentle tug with a wet hand [1][2]. 2. Rise: it has grown noticeably. The Perfect Loaf's beginner recipe looks for about 20–50% in that recipe [3]. 3. Domed edges and jiggle: the edges curve up where the dough meets the container, and the whole mass wobbles when you shake the bowl [1][2]. 4. Bubbles: visible on the surface and, in a clear container, along the sides [3]. 5. Temperature: if the dough is warmer than the recipe's target, expect to finish earlier; cooler, later [1].
How much rise? Two views
- By temperature. Sourdough Archive's chart aims for a bigger rise in cool dough and a smaller one in warm dough: about 75–100% at 65°F, 50–75% at 70°F, 30–50% at 75°F, 25–30% at 80°F and 20–25% at 85°F [5]. Its reasoning is that warm dough keeps fermenting for hours while it cools in the fridge, so it should go in earlier [5].
- By flour. The Perfect Loaf cautions against relying on rise alone: a 70% hydration white dough might nearly double, while a 100% hydration whole-wheat dough might grow only 20–30%, and both can be ready [1].
Both can be true. A straight-sided container with a mark (or a rubber band) at the starting level makes the rise easy to read. The Sourdough Journey builds a whole method on measuring dough temperature plus percentage rise [12].
Not the poke test
The poke test is for the final proof of a shaped loaf, not for bulk [1]. A dough can also pass a windowpane (stretch) test long before bulk is finished: the test shows gluten strength, not fermentation [5].
Speeding it up or slowing it down
| You want to… | Try | Source |
|---|---|---|
| Speed it up | Warmer mixing water; a warm spot. The Perfect Loaf wouldn't go above about 85°F | [1][9] |
| Use the oven as a warm spot | Light on, oven off. Check it with a thermometer: it can get hotter than you expect, and the oven's own proof setting may be too hot | [5][13] |
| Slow it down | Cooler mixing water, or ice water in a hot kitchen. The Perfect Loaf wouldn't go below about 39°F | [1][5] |
| Bake later than planned | Use less starter next time, or move the dough to the fridge (see below) | [4][5] |
Cold bulk and overnight bulk
You can stretch bulk across a night in two ways.
1. Cold bulk (bulk retard) in the fridge. The Perfect Loaf starts the bulk warm, typically for about half of the recipe's warm bulk time once the dough is visibly rising and puffy, then refrigerates it at 38–40°F for 4–24 hours [1]. Sourdough Archive suggests a much lower starter amount for this (5–10%) and a warm start of 20–30 minutes or more before the dough goes in the fridge [5]. A big mass of dough takes hours to cool, so it keeps fermenting in the fridge [1][5]. Food-safety agencies also recommend a fridge at 40°F or below in general [14]; a fridge thermometer tells you where yours actually sits.
2. Overnight bulk on the counter. The Pantry Mama mixes in the evening, lets bulk run overnight at room temperature and shapes in the morning. It recommends doing this only when the room is around 21°C (about 70°F) or cooler, and starting with a smaller amount of starter, about 50 g in its recipe, with more only if the kitchen is particularly cold [16]. The Clever Carrot's recipe likewise takes about 10–12 hours at 68°F [7]. A warm night is the risk: the same dough can be done in 3–4 hours at 80°F [5][7].
For whole schedules built around these options, see Overnight and Same-Day Sourdough.
Troubleshooting bulk fermentation
| What you see | Likely cause | What the sources suggest |
|---|---|---|
| Barely risen after the recipe's time | Cool dough, weak starter, or too little starter | Check the dough temperature, give it longer, and use warmer water next time [1][5]. Make sure the starter is rising reliably first (starter guide) |
| Surface flat or collapsing, large irregular bubbles, slack and sticky, strong alcohol smell | Over-fermented: too warm or too long [5] | Shorten bulk or use cooler water next time [5]. For a shaped loaf that has slightly over-proofed in the fridge, How To Make Sourdough suggests baking it straight away [17] |
| Sticky and weak at the end | Too much water, under-mixed, or ended too early | Hold back about 5% of the water next time, add one or two more sets of folds, and give it 15–30 minutes longer [1] |
| Loaf spreads flat after shaping | Bulk that ran too short or too long; in warm dough, gluten breakdown from going too far [5] | Adjust bulk next time using the signs above, or lower the hydration a few points with the baker's percentage calculator |
| Dense, tight crumb | Often under-fermented | Let bulk run longer, judged by the signs above [1][6] |
Keep a bulk log
Because temperature drives timing, the most useful notes are: room temperature, dough temperature after mixing, how long bulk ran and how much the dough rose. After a few bakes those four numbers give you a time for your kitchen. The free printable on the weekend schedule page has a log, and the Sourdough Schedule Pack has a "this bake" line on every timeline for exactly these numbers.
FAQ
How long should sourdough bulk fermentation take? At a dough temperature of about 74–78°F, most published recipes finish in roughly 3–5 hours [1][2][3]. Cooler dough, or a recipe with very little starter, can take 8–12 hours or more [4][5][6].
What temperature is best for bulk fermentation? There's no single best one [1]. A dough of about 75–78°F ferments at a predictable pace and is what many recipes target [1][9]. Warmer is faster and needs closer watching; cooler is slower.
Does bulk start when I add the starter or when I finish mixing? Sources word it slightly differently: British Sourdough counts from the moment the starter goes in [6]; The Perfect Loaf counts from the end of mixing [1]. On a single loaf the gap is small. Just be consistent in your notes.
Should I use the poke test to end bulk? No. The Perfect Loaf says the poke test is for the final proof of a shaped loaf [1]. Use the signs above.
How much should the dough rise during bulk? It depends on temperature and flour. One chart suggests about 30–50% at 75°F, more for cooler dough and less for warmer [5]; whole-grain doughs may rise only 20–30% and still be ready [1].
Can I bulk ferment in the fridge? Yes: start it warm until it's visibly rising, then refrigerate at 38–40°F. Published times run from 4 to 24 hours [1], usually with less starter in the dough [5].
Should I cover the dough? Yes. A lid or cover stops a dry skin from forming, which could hold back the rise [1].
My dough is still sticky at the end of bulk. What now? Hold back about 5% of the water next time, add a set or two of stretch and folds, and give bulk 15–30 more minutes [1].
Related: - Overnight and Same-Day Sourdough: Pick a Schedule That Fits Your Day - A Weekend Sourdough Schedule You Can Print - Sourdough Starter: How to Make It, Feed It, and Fix It - Baker's Percentages & Hydration Calculator
Sources (checked 2026-10-17)
- The Perfect Loaf (Maurizio Leo), "The Ultimate Guide to Bread Dough Bulk Fermentation" (updated 2026-04-16): https://www.theperfectloaf.com/guides/the-ultimate-guide-to-bread-dough-bulk-fermentation/
- King Arthur Baking (Maurizio Leo), "Bulk fermentation, explained" (2019-07-22): https://www.kingarthurbaking.com/blog/2019/07/22/bulk-fermentation
- The Perfect Loaf, "Beginner's Sourdough Bread" (updated 2026-01-15): https://www.theperfectloaf.com/beginners-sourdough-bread/
- King Arthur Baking, "Sourdough schedule: How to plan your bread baking timeline" (2026-05-20): https://www.kingarthurbaking.com/blog/2026/05/20/sourdough-starter-feeding-schedule
- Sourdough Archive, "Sourdough Bulk Fermentation Chart: Complete Temperature + Time Guide": https://sourdougharchive.com/sourdough-bulk-fermentation-chart/
- British Sourdough, "Bulk Fermentation for Sourdough: Using Temperature Not Time" (2026-04-17): https://britishsourdough.com/bulk-fermentation-for-sourdough-using-temperature-not-time/
- The Clever Carrot, "Sourdough Bread: A Beginner's Guide": https://www.theclevercarrot.com/2014/01/sourdough-bread-a-beginners-guide/
- Country Roads Sourdough, "Same Day Sourdough Bread": https://countryroadssourdough.com/same-day-sourdough-bread/
- King Arthur Baking, "Desired dough temperature" (2018-05-29): https://www.kingarthurbaking.com/blog/2018/05/29/desired-dough-temperature
- King Arthur Baking (Pro), "Dough Temperature": https://www.kingarthurbaking.com/pro/reference/dough-temperature
- America's Test Kitchen, "Precise Water Temperature for the Perfect Loaf": https://www.americastestkitchen.com/how_tos/5818-precise-water-temperature-for-the-perfect-loaf
- The Sourdough Journey (Tom Cucuzza), "The Ultimate Sourdough Bulk Fermentation Guide" (2024-08-24): https://thesourdoughjourney.com/the-ultimate-sourdough-bulk-fermentation-guide/
- King Arthur Baking, "Sourdough Starter" recipe (warm-spot tip; check the temperature): https://www.kingarthurbaking.com/recipes/sourdough-starter-recipe
- US FDA, "Refrigerator Thermometers: Cold Facts about Food Safety": https://www.fda.gov/food/buy-store-serve-safe-food/refrigerator-thermometers-cold-facts-about-food-safety
- The Perfect Loaf, "Simple Weekday Sourdough Bread": https://www.theperfectloaf.com/simple-weekday-sourdough-bread/
- The Pantry Mama, "Overnight Sourdough Bread": https://pantrymama.com/overnight-sourdough-bread/
- How To Make Sourdough, "Cold Retard in Sourdough: What It Is and Why It Matters": https://howtomakesourdough.ca/cold-retard-in-sourdough-what-it-is-and-why-it-matters/