Tag: overproofing

High-Altitude Sourdough: Why Your Loaf Changed When You Moved Up the Mountain
You had it figured out. The recipe, the schedule, the way the dough felt under your hands, all of it dialed in after months of practice. Then you moved, or started baking at the cabin, and the very same loaf came out wrong. Flatter. Drier. Overblown and then collapsed. Nothing in your routine changed except one thing: your elevation.

If your sourdough suddenly misbehaves after a move up the mountain, you are not losing your touch. Altitude genuinely changes the physics of your dough, and once you understand what shifted, the fixes are simple and consistent. Let’s walk through what altitude actually does, from the cause you’ll feel first to the ones hiding in the background, and exactly how to adjust.

Same recipe, higher ground: altitude quietly rewrites how your dough behaves.

What high altitude actually changes

Three things shift as you climb, and they all trace back to one fact: the higher you go, the lower the air pressure.

First, lower pressure means gases expand more freely. The carbon dioxide your starter produces pushes against less resistance, so dough rises faster and further. Second, the air is usually much drier at elevation, so your dough and its surface lose moisture more quickly than they did at sea level. Third, water boils at a lower temperature, which subtly changes how heat and steam behave in your oven. Most home bakers feel these effects strongly starting around 3,000 feet, and they get more pronounced the higher you go. Let’s take them in the order they’ll bite you.

Cause one: everything ferments faster, so you overproof without noticing

This is the big one, and it’s almost always the first thing to go wrong. With less air pressure holding the dough back, fermentation gas expands more and your loaf races through bulk fermentation and the final proof. The schedule that gave you a perfect loaf at sea level now carries the dough right past its peak.

The flatter loaf on the right is the classic altitude tell: it proofed faster than you expected.

An overproofed loaf spreads instead of rising, tears raggedly, bakes dense and gummy, and loses its oven spring. If that sounds like your new altitude loaf, this is your culprit. The fix is to stop trusting the clock and start trusting the dough. Watch for the real signs that bulk fermentation is done, a 30 to 50 percent rise, a domed and jiggly surface, a few bubbles at the edges, rather than a set number of hours. You will likely find the dough is ready noticeably sooner than your old routine said.

You can also slow the whole process down to give yourself margin: use a little less starter in the dough, keep your fermentation space a touch cooler, or lean harder on a cold retard in the fridge. If you are still unsure which way your loaf failed, our guide to telling overproofed from underproofed sourdough will help you read the signs before you commit to a change.

Cause two: the dry air stiffens your dough

At elevation the air is thirsty. It pulls moisture out of your dough during mixing, folding, and shaping, and it dries the surface skin faster than you’re used to. The result is a dough that feels tighter and stiffer than the same recipe did at sea level, which can hold back the open, airy crumb you want and make shaping fight you.

Thinner air lets fermentation gases expand more, so everything moves faster up high.

The fix is usually a small bump in hydration. Try adding an extra two to four percent water to your recipe (for a loaf using 500 grams of flour, that’s roughly 10 to 20 grams more water) and see how the dough responds. Add it gradually; you want the dough supple, not soup. If the new wetter dough feels unmanageable at first, our tips for handling sticky, high-hydration dough will keep it from turning into a mess on the counter. Keeping your dough covered between steps matters more than ever up high, so the surface doesn’t dry into a tight skin that resists rising.

Cause three: wild oven spring, then a flat or collapsed loaf

Dry mountain air pulls moisture from the dough, so a touch more water often restores it.

Altitude can give you dramatic early oven spring, the dough leaps, because the gases inside expand so eagerly in the heat. That sounds great until the structure, already stretched thin by fast fermentation, can’t hold the expansion and the loaf collapses or spreads into a disc. A loaf that balloons and then falls, or simply bakes flat and wide, is telling you the gluten network gave out under pressure it wasn’t built to handle.

The answer is stronger structure and a slightly earlier bake. Build good tension when you shape, since a well-shaped, taut boule resists spreading far better than a slack one; if your loaves keep flattening, revisit how to fix a sourdough that spreads instead of rising tall. And because fermentation runs fast, aim to bake when the dough is a touch underproofed rather than perfectly proofed by sea-level standards. That extra reserve of strength gives the loaf something to push against in the oven instead of blowing out and deflating.

Cause four: the oven itself behaves differently

This one is subtle but worth knowing. Because water boils at a lower temperature at altitude, steam forms more readily and moisture escapes your loaf a little faster during the bake. In practice, two small adjustments help. Keep your Dutch oven covered or your steam in place for the full first phase so the crust stays flexible long enough to spring, then uncover and finish with a good dry, hot stretch to drive out the extra moisture and set a crust that lasts.

You generally do not need to crank the oven hotter; if anything, a very high elevation loaf can benefit from a slightly lower temperature and a minute or two longer, so the inside finishes before the crust over-darkens. Bake to a deep golden-brown and, if you use a thermometer, to an internal temperature around 205 to 210 degrees Fahrenheit (96 to 99 Celsius), regardless of what the clock says.

Your high-altitude adjustment cheat sheet

Pulling it together, here is where to start when you bring a sea-level recipe up the mountain. Change one or two things at a time so you can see what’s working:

Use a little less starter, or ferment a touch cooler, to slow things down. Judge bulk by the dough’s rise and feel, not the clock, and expect it to finish earlier than before. Add a small amount of extra water to counter the dry air, and keep the dough covered at every rest. Shape with real tension and bake slightly on the underproofed side to protect your oven spring. Keep it covered or steamed through the first phase, then finish dry and hot, baking to color and internal temperature rather than time.

Dial in the timing and even thin air gives you the spring you are chasing.

Putting it all together

A sourdough loaf that changed the day you changed elevation is not a broken recipe or a lost skill. The thin, dry mountain air simply speeds your fermentation, stiffens your dough, and super-charges your oven spring, so the schedule and hydration that were perfect lower down now need a nudge. Slow the ferment, read the dough instead of the clock, add a little water, build strong structure, and bake to color. Give it two or three bakes of small tweaks and your old loaf, the tall, open, crackling one, comes right back, thin air and all.

Want to watch these adjustments in real time, from reading a fast bulk ferment to shaping for spring? The full walkthrough lives on the LoafLovers YouTube channel, and our free sourdough troubleshooting guide covers overproofing, flat loaves, and dry dough in the same symptom-to-fix format. Your mountain kitchen isn’t working against you. It just needs a slightly different conversation with the same good dough.

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October 15, 2026
Why Did My Sourdough Deflate? Fixing Dough That Collapses When You Turn It Out or Score It
There are few more deflating moments in home baking — literally — than this one. You’ve babied the dough for the better part of a day. It looked plump and promising in the banneton. Then you tip it out, and it slowly spreads into a sad, flat puddle before your eyes. Or worse: it holds its shape right up until your blade touches the surface, and then the whole loaf sighs and sinks like a punctured tire. All that gas, gone in a second.

Take a breath. Deflation feels like a mystery, but it almost never is. It traces back to a short list of causes, and every one of them is fixable once you can spot which is yours. Let’s diagnose it and make sure the next loaf stays standing.

The heartbreak moment: the dough leaves the banneton and slowly spreads instead of standing proud.

First, what deflation actually is

Your dough is a balloon — a network of gluten holding thousands of tiny gas bubbles the yeast and bacteria have produced. A loaf that deflates has lost the ability to hold that gas. Either the balloon’s walls have gotten too weak to contain the pressure, or you’ve physically punctured them. So every cause of deflation is really an answer to one of two questions: was the structure too fragile, or did something pop it? Keep that frame in mind and the fixes organize themselves.

Cause #1: The dough was overproofed (the most common culprit)

This is the number one reason dough collapses on contact. When dough proofs for too long, the yeast and bacteria keep working — producing acid and gas — until the gluten network is stretched past its limit and starts to break down. It becomes slack, delicate, and unable to support itself. An overproofed loaf can look gorgeously puffy in the banneton precisely because it’s maxed out; there’s no strength left in reserve. So the moment you turn it out or nick it with a blade, it has nothing to fall back on and it collapses.

How to tell it’s overproofing: the dough felt very slack and almost soupy, showed lots of large surface bubbles, and gave off a sharply sour smell. The classic confirmation is the poke test — press a floured finger into the dough and the dimple stays put and doesn’t spring back at all. If that’s you, the fix is to shorten the proof.
- Pull the dough earlier. Especially in a warm kitchen, fermentation runs faster than most guides assume. Learn to read the dough rather than the clock — our guide to telling overproofed from underproofed walks through exactly what to look for.
- Use the poke test properly. When the dimple springs back slowly and only partway, it’s ready. When it doesn’t spring back at all, you’ve gone too far. See the full method in how to use the poke test.
- Cold-proof for control. Retarding the shaped loaf in the fridge slows things right down and gives you a much wider, more forgiving window to bake in.
The poke test tells you whether the dough is ready or already over the edge into fragile territory.

Cause #2: The gluten was never strong enough to begin with

Sometimes the dough isn’t overproofed — it simply never developed the structure to hold its shape in the first place. Under-developed gluten produces a batter-like dough that can’t trap gas efficiently and sags the instant it loses the support of the bowl or banneton. This is a structure problem, not a timing one.

The usual reasons: not enough stretch-and-folds during bulk, too little strength-building for a high-hydration dough, or flour that’s simply too weak (low protein) for the job. The fixes:
- Build more strength during bulk. A few well-timed stretch-and-folds transform a slack dough into one that holds tension. Don’t skip them, especially on wetter doughs.
- Check your gluten before you shape. The windowpane test tells you whether the network is actually ready to hold gas — a quick way to catch weak dough before it ever reaches the banneton.
- Look at your flour. A low-protein flour struggles to build a strong network under a long, wet ferment. If your dough is chronically slack, a stronger bread flour is one of the highest-leverage changes you can make.
Cause #3: You knocked the gas out during transfer

Now the mechanical causes — the times the dough was fine but your handling popped the balloon. Turning a proofed loaf out of the banneton is a genuinely delicate moment, and rough handling here undoes hours of careful work.
- Invert, don’t squeeze. Turn the banneton over and let gravity release the dough. Don’t shake it violently, dig it out, or press on it — every squeeze crushes bubbles you can’t get back.
- Turn out onto parchment, then transfer. Tip the loaf directly onto a sheet of parchment so you can lift the whole thing into the pot without ever handling the soft dough again. Fumbling a bare loaf from hand to pot is a classic deflation moment.
- Fix sticking first. If the dough clings and you have to yank it free, it tears and deflates on the way out. Flour the banneton well — and if this keeps happening, see our fix for dough that sticks to the banneton.
Cause #4: Scoring went wrong

If the loaf holds up beautifully until the blade touches it, scoring is your suspect. A few things cause a score to deflate a loaf instead of decorating it:
- A dull or dragging blade. A sharp lame slices cleanly through the surface. A dull one drags and pulls at the skin, tearing the gluten and letting the gas escape in a rush. Use a fresh, sharp blade every time.
- Scoring too deep or hesitantly. Deep, sawing cuts sever too much of the structural skin. You want one confident, shallow-to-moderate stroke, not a slow, tentative gouge.
- Warm, slack dough at the blade. This is the big one. Room-temperature dough is soft and easily torn; cold dough straight from the fridge is firm, taut, and scores like a dream. Scoring cold is the single easiest way to stop deflation-on-scoring — and it also gives you a better ear and oven spring as a bonus.
A confident, shallow score on cold, taut dough glides in — a dragging blade on warm dough tears and deflates.

Cause #5: Weak shaping left nothing to hold the gas

Shaping isn’t just about making the loaf look round — it builds the taut outer “skin” of tension that acts as a scaffold, holding the gas in and the loaf up. A slack, under-tensioned shape has no scaffold, so the loaf relaxes and spreads the moment it’s unsupported, even if the dough itself is perfectly proofed.

The fix is to shape with real intent: create surface tension by dragging the dough gently across an unfloured patch of counter until the top is taut and domed, then let it rest seam-side up in the banneton to set. If your rounds always seem to relax and flatten, our walkthrough on shaping a boule with real tension shows exactly how to build a skin that holds. Well-shaped dough forgives a lot of small sins elsewhere; slack shaping punishes everything.

Your quick deflation diagnosis

Put it all together and you can pinpoint the cause in seconds by asking when the collapse happened:
- Spread slowly into a puddle after turning out? Overproofing or weak gluten/shaping. Proof less, build more strength, shape tighter.
- Sank the instant the blade touched it? Scoring — use a sharp blade, cut confidently, and score cold dough straight from the fridge.
- Deflated while you were manhandling it out of the banneton? Transfer technique — invert gently onto parchment, no squeezing, and fix any sticking.
- Looked perfect but felt fragile the whole time? Almost certainly overproofed — catch it earlier next time.
A tight shaping skin is the scaffold that holds the gas in — slack shaping is deflation waiting to happen.

The bottom line

A deflating loaf isn’t bad luck — it’s a message. Either the structure was too fragile to hold its gas (overproofed, under-developed, or weakly shaped) or something physically popped it (rough transfer or a bad score). Work through the five causes in order, and the fixes are refreshingly simple: proof a little less, build strength during bulk, shape with real tension, handle the dough gently on the way out, and score cold with a sharp blade. Change one thing at a time so you can see what worked, and the next loaf will turn out of the banneton standing tall and hold its breath right through the oven.

Fix the cause of the collapse and this is what turns out of the banneton instead.

Want to see a gentle turn-out and a clean, confident score in real time? The full visual walk-through — plus our free sourdough troubleshooting guide — lives on the LoafLovers YouTube channel. Come watch exactly where the deflation happens, and how to stop it.

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September 26, 2026
Why Is My Sourdough Flat? Fixing Loaves That Spread Instead of Rising Tall
You slid the dough into the oven hoping for a tall, domed loaf with a bold ear – and twenty minutes later you’re looking at something low, wide, and spread out like a frisbee. No lift, no drama, just a sad puck of bread. It’s one of the most deflating moments in sourdough, and if you’re standing at the oven door right now wondering what went wrong, take a breath. A flat loaf is not a mystery. It’s a symptom, and it almost always points to one of a handful of specific causes.

The trick is that several different problems all end in the same flat result, so the fix depends entirely on which one bit you this time. Let’s read the clues on the loaf in front of you and match them to the real cause – then fix it for good.

Same recipe, two outcomes: a flat spreader on the left, a tall loaf with real oven spring on the right.

What a Flat Loaf Is Actually Telling You

A loaf rises tall for two reasons working together: the dough holds a strong, gas-tight gluten structure, and that structure has enough tension to push up rather than out when it hits the heat. When a loaf spreads flat instead, one of those two things failed – the structure was too weak to hold the gas, or the tension that would have directed the rise upward was never there.

That splits every flat loaf into two families. In the first, the dough was over-fermented – it rose beautifully at some point, then the gluten broke down and could no longer hold its shape, so it slumped. In the second, the dough was structurally weak from the start – underdeveloped gluten, too much water for your skill level, a tired starter, or a slack shape – so it never had the backbone to rise in the first place. Knowing which family you’re in is the whole game.

How to Tell Which Problem Is Yours

Before you fix anything, diagnose it. Think back over the last few hours and answer these:
- How did the dough feel at shaping? Slack, sticky, and unwilling to hold a ball points to overproofing or too-high hydration. Firm and springy but flat anyway points to shaping or oven problems.
- Did it spread the moment you turned it out of the banneton? If it puddled outward before it ever saw heat, the structure was already gone – suspect over-fermentation, a weak starter, or a dough that was simply too wet and too warm.
- Did it hold its dome on the counter but refuse to spring in the oven? That’s a heat-and-steam problem, or a shape with too little tension to climb.
- What did it smell like? A sharp, boozy, acetone or nail-polish note means fermentation ran long. A mild, pleasant tang means fermentation was probably fine and the fault is elsewhere.
Hold those answers in mind. As we walk through each cause below, you’ll see your loaf in one of them.

A dough that puddles the moment it leaves the banneton has lost its structure before it ever reached the oven.

Cause 1: The Dough Overproofed

This is the single most common reason a loaf spreads. Overproofing – whether from an over-fermented bulk, a too-long final proof, or dough that sat somewhere too warm – means fermentation ran past the dough’s peak. The yeast kept producing acid and gas long after the gluten could cope, and the network that was holding everything taut slowly dissolved. By the time it hits the oven there’s no structure left to spring, so it flows outward instead of rising.

The tells: slack, sticky, hard-to-handle dough at shaping; a shaped loaf that flattens on the counter instead of holding its dome; little to no oven spring; and that sharp, boozy smell. A poke test seals it – if you press a floured finger in and the dent stays put or the dough sighs and deflates, it’s overproofed.

The fix: shorten fermentation and watch the dough, not the clock. Most home bakers over-ferment because they trust a recipe’s “bulk for 4 hours” in a kitchen that’s warmer than the recipe assumed. End bulk when the dough has risen roughly 50-75% and looks domed, jiggly, and alive – not when the timer says so. Use an aliquot jar (a pinch of dough in a straight-sided jar, marked at the start) so you can read the rise precisely. And keep your dough cooler: warmth is the accelerator here, which brings us to the next culprit.

Cause 2: The Dough Was Too Warm

Temperature is the throttle on your entire bake, and a warm kitchen is the quiet reason so many loaves overproof without the baker realizing it. Dough ferments dramatically faster as it warms – a batch at 26 C / 78 F can be racing through bulk while the recipe was written for a calm 22 C / 72 F. You follow the times exactly and still end up past peak, because your kitchen was running hot the whole time.

The fix: take your dough’s actual temperature with a probe thermometer and aim for a target dough temperature around 24-25 C / 75-77 F. If your kitchen runs warm, use cooler water when mixing, shorten the bulk, and lean on the fridge for the final proof. Cold, slow fermentation is far more forgiving – it widens the window where the dough is perfectly ready, so you’re less likely to blow past it.

Cause 3: A Weak or Under-Strength Starter

If your dough never really came alive – sluggish bulk, barely any rise, dense and flat at the same time – look at your starter before you blame your technique. A young, neglected, or under-fed starter simply can’t generate the gas and acidity a loaf needs, and no amount of good shaping will save a dough that had a weak engine.

A strong starter at peak – domed, bubbly, and lively – is the engine behind a tall loaf.

The fix: feed your starter on a reliable schedule and only bake when it’s at peak – domed, bubbly, and roughly doubled within 4-8 hours of feeding. The float test is a quick confidence check: a spoonful that floats in water is full of gas and ready to work. If yours is sluggish, give it a few days of consistent feedings (try 1:2:2 or 1:3:3 starter-to-flour-to-water by weight) somewhere warm before your next bake. A strong starter is the cheapest upgrade to your bread there is.

Cause 4: Weak Gluten and Too-Slack Dough

Gluten is the scaffolding that traps gas and holds the loaf’s height. If it’s underdeveloped – not enough mixing, too few stretch-and-folds, or a flour too low in protein – the dough stays extensible and floppy instead of strong and elastic, and it spreads under its own weight. The same thing happens when the hydration is simply too high for your current skill level: a very wet dough can make a gorgeous open crumb in experienced hands, but for many bakers it just puddles.

The fix: build more strength and, if you’re struggling, take some water out. Give the dough a proper set of stretch-and-folds or coil folds during bulk – usually three or four sets in the first couple of hours – until it feels smooth, tight, and holds its shape. Do a windowpane check: stretch a small piece thin; if it goes translucent without tearing, your gluten is there. And there’s no shame in dropping hydration. If your recipe calls for 80% and you’re fighting a soupy mess, come down to 68-72% until you’re consistently getting tall loaves, then climb back up. A strong dough at lower hydration beats a slack one at high hydration every time.

Cause 5: Not Enough Shaping Tension

Even a perfectly fermented, well-developed dough will spread if you shape it loosely. Shaping is where you build the taut outer skin that holds the loaf together and directs the oven spring upward instead of outward. Skip that tension and the dough has nothing to climb.

Shaping is where you build the taut skin that holds the loaf tall – drag and cup until the surface tightens.

The fix: shape with intent. After a gentle pre-shape, let the dough rest 20-30 minutes so it relaxes, then do a final shape where you build real surface tension – fold the dough over itself and drag the taut ball across an unfloured patch of counter, cupping your hands around it so friction tightens the skin. You want to feel it firm up under your hands. A well-shaped loaf should sit up as a proud, tight round or oval, not sag. This one habit rescues more flat loaves than any other single change.

Cause 6: A Cold Oven and No Steam

Sometimes the dough was fine and the oven let you down. Oven spring – that final dramatic rise in the first ten minutes – depends on two things: intense heat that sets the crust fast enough to trap the rise, and steam that keeps the crust soft and stretchy long enough for the loaf to expand before it hardens. Bake in a cool oven or a dry one, and the crust sets too soon, the loaf can’t push up, and it settles wide.

Trapped steam plus a screaming-hot start is what turns a good dough into a tall, blistered loaf.

The fix: preheat hard and trap steam. Get your oven fully up to temperature – usually 230-250 C / 450-480 F – and preheat a Dutch oven or baking stone inside it for a good 45 minutes so it’s genuinely screaming hot when the dough goes in. The easiest way to guarantee steam is to bake in a covered Dutch oven for the first 20 minutes; the loaf steams itself in its own moisture, then you remove the lid to brown and crisp. If you bake on a stone, add steam with a preheated tray of water or a few ice cubes. Hot start, trapped steam, tall loaf.

Your Next-Bake Fix List

Put it together and the flat loaf stops being a mystery. Next time, run down this short list: bake with a starter at peak; keep your dough temperature around 24-25 C and end bulk by rise, not by clock; develop the gluten until it passes the windowpane and drop hydration if you’re fighting the dough; shape with real surface tension; and load it into a screaming-hot, steamy oven. Change one thing at a time so you learn which lever mattered for your kitchen, and you’ll watch the loaves climb.

Want to see the shaping tension, the poke test, and a proper Dutch-oven load in real time? The full fix – with close-ups of every step – lives on the LoafLovers YouTube channel. And if you’d like a one-page cheat sheet to keep by the oven, grab our free sourdough troubleshooting guide when you join the email list. No hard sell, just the answers for your next bake.

Sources & further reading:
- The Perfect Loaf – Why Is My Sourdough Bread Flat?
- King Arthur Baking – Sourdough Troubleshooting
Related: Why Is My Sourdough Gummy? The Real Causes of a Dense, Underbaked Crumb (and How to Fix It)

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August 11, 2026