Sourdough proofing chart: final proof and cold retard times

Final proof is the short stage. At room temperature it runs 45 minutes to 2 hours; cold, it runs 8 to 36 hours depending on how cold your fridge actually is. The sourdough proofing chart below covers both routes by temperature.

Final proof and bulk fermentation are not the same clock

Most loaves that get called overproofed were overproofed in bulk, not in the banneton. Bulk fermentation is the long unshaped stage after mixing: several hours at room temperature, ending when the dough has risen roughly 30–50%, feels airy, and holds a domed edge instead of pooling. Nearly all the gas and nearly all the risk live there. Bulk fermentation gets its own chart, because the variables that move it are different.

Final proof happens after shaping, and it only finishes what bulk started: relaxing the dough enough to expand in the oven without letting the tension you built during shaping go slack. If bulk ran to completion, final proof is genuinely short. Sourdough proofing times that look absurd, like "proof four hours after shaping," usually belong to recipes that ended bulk early.

Two variables move the number more than anything else: dough temperature and how far bulk actually went. Hydration matters too, though hydration mostly changes how the dough looks at the finish line rather than when it arrives. An 85% dough spreads at the point where a 70% dough still domes.

Sourdough proofing chart: final proof by temperature

Dough / fridge temp	Final proof window	What it means in practice
78–82°F (26–28°C)	45 min – 1 hr 15 min	Fast and unforgiving. Start checking at 40 minutes.
74–77°F (23–25°C)	1 – 2 hr	The standard warm-kitchen room-temperature proof.
68–73°F (20–23°C)	2 – 3 hr	Cool kitchen. The "two hours maximum" rule stops applying here.
40–42°F (4–6°C)	8 – 14 hr	A warm fridge. Fermentation slows but never stalls, so treat it as an overnight window, not a two-day one.
37–39°F (3–4°C)	12 – 24 hr	The dependable sourdough cold proof range.
34–36°F (1–2°C)	18 – 36 hr	Close to a stall. This is the band that makes two-night schedules work.

Every row is a window, and where you land inside it depends on bulk:

• Bulk ended early. Take the long end. The dough still has fermenting left to do and will do most of it in the first hours of the retard.
• Bulk ran long. Take the short end, or skip the retard and bake the same day.
• Whole grain or high rye. Take the short end regardless. Those flours ferment faster and degrade sooner.

How long to proof sourdough in the fridge

A cold retard doesn't start cold. A shaped 900-gram boule going into a 38°F fridge needs roughly two to four hours before its center is anywhere near that temperature, and all through that cooling it ferments at a rate somewhere between kitchen speed and fridge speed. A "twelve-hour retard" is really a short room-temperature proof stacked on a long cold one. Put the basket on a lower back shelf rather than the door, and it crosses that gap faster.

Measure the fridge. Dials are settings, not readings, and the shelf where the basket sits can be several degrees off what the dial claims. The door is usually the warmest spot in the box, the back of the bottom shelf the coldest. Two fridges both set to "4" can put you at opposite ends of the chart above, which is the whole reason for charting by temperature rather than quoting one number.

The most common sourdough overnight proof failure isn't the temperature, though. It's a retard that runs six hours past plan because nobody wrote down when it started. Noting the time the dough went in and the time you intend to pull it out takes the arithmetic out of a decision made at bedtime. Sourdough Tracker, a sourdough baking companion app for iPhone, is one place to keep those timestamps.

How to tell if sourdough is proofed: calibrating the poke test

The poke test reads gluten relaxation, which tracks fermentation closely enough to bake by. Flour a fingertip, press about half an inch into the dough, away from the seam, then watch what the dent does:

• Springs back fully within a second or two: underproofed. Give it more time and check again in 20 minutes.
• Springs back most of the way, slowly, leaving a shallow dent: ready. Score and bake.
• Doesn't spring back at all, and the dough around the dent sighs or spreads: overproofed. Bake immediately, score shallow, and expect a flatter loaf with an open, wet-ish crumb.

Cold dough is the exception. Straight from the fridge, gluten is stiff and recovers slowly no matter how the fermentation went, so a retarded loaf can read "ready" whether it's under or over. On cold dough, judge the other signals: does it hold its dome when tipped from the basket, or slump toward a puddle; is the surface freckled with small bubbles, or one big raised blister that suggests it went too far; does the seam still hold. The sourdough poke test is a room-temperature instrument.

The float test answers a different question: whether the starter is at peak. It doesn't transfer to shaped dough.

What a retard past 24 hours costs

Longer isn't automatically better. Between roughly 12 and 24 hours at 37–39°F you gain flavor depth plus a firm, cold dough that scores like butter. Past 24, the trade shifts:

• Sourness climbs, and changes character. Cold, slow conditions favor acetic acid over lactic, so the tang gets sharper and more vinegary rather than mellow and yogurt-like.
• Oven spring drops. Enzymes keep loosening gluten while yeast activity is throttled by the cold, so the dough gets slacker without getting gassier.
• Scores lose definition. A slack skin tears sideways instead of opening into a clean ear.

Plenty of bakers want the 36-hour loaf for exactly that sharpness and the blistered crust that comes with it. That's a preference, not an error. Just don't expect the same height from it.

Building the retard around your schedule

Work backward from the bake, not forward from the mix. Shape at 9 p.m., fridge at 40°F, bake at 7 a.m.: that's ten hours, comfortably inside the window. Move the bake to noon and it's fifteen hours, still fine at 38°F but tight at 41°F.

When the schedule can't move, move the fermentation instead. End bulk 30 to 45 minutes earlier, or run bulk a couple of degrees cooler, so the dough enters the fridge with more work left. For a two-night retard, do both, and set the fridge to its coldest setting a few hours before the dough goes in.

FAQ

How long can sourdough sit in the fridge before baking?

Up to about 36 hours at 34–36°F, 12–24 hours at 37–39°F, and 8–14 hours in a fridge running 40°F or warmer. It won't spoil past those windows; it just keeps getting sourer and slacker, and trades away oven spring.

Should I bake sourdough straight from the fridge?

Yes, in most cases. Cold dough is firmer, scores cleanly, and holds its shape through the first minutes in the oven, which is when the loaf decides how tall it's going to be. There's no need to let it warm on the counter first.

Can you overproof sourdough in the fridge?

Yes, especially in a fridge running at 40°F or above, or when the dough went in already fully bulk-fermented. The cold slows fermentation dramatically but doesn't switch it off, and the first hours before the dough chills through are close to room-temperature speed.

Why doesn't my dough rise in the fridge?

Mostly it isn't supposed to. Visible expansion during a cold proof happens in the first few hours while the dough is still losing heat; after that the loaf can look identical at 7 a.m. to how it looked at midnight and still be perfectly proofed. Judge it by feel and by how it behaves in the oven, not by the height in the basket.