Overnight Sourdough Batard

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Here’s the truth about overnight sourdough: it’s better. The cold fermentation develops deeper, more complex flavor. It gives you control over timing. And at 7,000 feet where everything moves fast, that overnight rest in the fridge is your insurance policy against over-fermentation.

This isn’t a same-day bread. This is the loaf you start after dinner and bake the next morning. It’s the one that fills your kitchen with that unmistakable sourdough aroma while you’re having your coffee. It’s worth the wait.

Why Overnight Fermentation Works at Altitude

At 7,000 feet, fermentation happens faster than sea-level recipes account for. The overnight cold retard slows everything down, giving the dough time to develop flavor without racing past the optimal fermentation window. Plus, cold dough is easier to score and holds its shape better when you load it into a screaming-hot oven.

The addition of diastatic malt powder helps with crust color and oven spring at altitude. It’s optional, but it makes a difference.

Getting Your Starter Ready

Before you do anything else, check your starter. This recipe requires a healthy, active starter that’s doubled in size 4-6 hours after feeding. Look for lots of bubbles throughout, a pleasant yogurt-like smell (not sour or acidic), and a thick consistency that’s not runny.

If your starter isn’t there yet, don’t start this recipe. Your bread is only as good as your starter, and there’s no technique that can compensate for weak fermentation.

The Mix · Building Strength from the Start

Place your KitchenAid bowl on the scale and add everything in order: 255g water at 80-85°F, 140g active starter, 190g bread flour, 190g AP flour, 6g diastatic malt powder (if using), and 9g salt.

This time we’re mixing more aggressively than the same-day recipe. Three minutes on speed 2, then three minutes on speed 4. You’re building serious gluten development right from the start. The dough should be smooth, elastic, and pulling cleanly away from the bowl. Target final dough temperature: 75-78°F.

Bulk Fermentation · Watch for the Signs

Leave the dough in the KitchenAid bowl and cover with a tea towel. Over the next 3-4 hours, you’ll perform 3-4 sets of stretch and folds right in the bowl, spaced 45-60 minutes apart.

To fold: wet your hands, grab one side of the dough, stretch it up, and fold it over itself. Rotate the bowl and repeat 3-4 times.

What you’re looking for:

• Dough nearly doubles in size (30-40% increase at altitude)
• Light and airy texture – like a fluffy marshmallow
• Domed top pulling away from sides like a muffin top
• When you shake the container, the entire mass moves together
• Dough comes away cleanly from sides when pulled
• Plenty of bubbles visible through the container

At 7,000 feet, this happens faster than you think. Trust the visual cues, not the clock.

Shaping · Creating Structure for a Batard

Turn your dough onto a lightly floured surface. Using your bench scraper, push down and around to form a tight round. Let this sit uncovered for 15 minutes. This rest period lets the gluten relax and forms a light skin that prevents sticking during final shaping.

Now for the letter fold method to create your batard shape: flip the dough over, stretch it gently into a rectangle, fold the bottom third up, fold the top third down like you’re folding a letter, turn 90 degrees, and roll it up tightly into an oval shape. You’re building tension without smashing out all the gases. Pinch the seam closed.

Place the dough seam-side up in a well-floured oval banneton (or oval-shaped bowl lined with a floured towel) and cover tightly with plastic.

The Game-Changer · Room Temp Then Cold

Here’s where this recipe differs from most overnight methods: after shaping, you’ll proof at room temperature for 1-2 hours before refrigerating. This gives the dough a head start on fermentation while you can still watch it, then the cold retard slows everything down for 8-12 hours overnight.

Why This Works at Altitude:

If you shape your dough and immediately stick it in the fridge, fermentation stops cold and the dough stays tight and tense from shaping. The next morning, it needs significant time to wake up and relax – sometimes 2-3 hours or more. By giving it 1-2 hours at room temp post-shape, you’re intentionally pushing fermentation forward while you have control over it.

At 7,000 feet where fermentation already moves fast, this technique gives you predictability. You’re front-loading some of your final proof so you’re not gambling on how much the dough will ferment overnight (which varies with fridge temperature and other factors you can’t control as easily).

The Timeline:

• Shape dough → place in banneton
• Proof 1-2 hours at room temp, covered
• Refrigerate 8-12 hours overnight
• Remove from fridge the next morning

This two-stage approach gives you the best of both worlds: developed flavor from the long ferment, control from the cold temperature, and a more predictable bake window the next morning.

Understanding Proof · The Make or Break Moment

The next morning, pull your dough from the fridge and let it sit covered at room temperature for 1 hour. This is where you need to pay attention.

Under-Proofed Dough: Springs back immediately when poked, feels very tight and dense, will likely tear during scoring. Results in dense crumb and explosive oven spring that can blow out the sides.

Properly Proofed Dough: Springs back slowly when poked, leaving a slight indentation. Feels soft and pillowy but still holds its shape. Has a slight dome and looks “full.” This is what you want.

Over-Proofed Dough: Doesn’t spring back when poked – the indentation remains. Looks flat or spreading. Results in a flat loaf with poor oven spring.

At 7,000 feet, err slightly on the side of under-proofed. The lower air pressure means dough will spring more aggressively in the oven.

Cold Dough vs. Room Temperature · The Oven Spring Debate

Should you bake straight from the fridge or let the dough warm up? This is where bakers argue, and at 7,000 feet, the answer actually matters.

The Case for Cold Dough: Cold dough straight from the fridge scores like a dream. The blade cuts through cleanly without dragging or sticking, giving you sharp, dramatic ears. The firm surface tension holds its shape better during scoring, and you’re less likely to deflate the dough while working with it. Some bakers swear by this method, especially for high-hydration doughs.

The Case for Room Temperature Dough: Room temperature dough gives better oven spring because the yeast and bacteria are more active when they hit the heat. The warmer dough starts expanding immediately, pushing up against the score lines and creating that explosive rise. The crumb tends to be more open with better overall volume. The downside? It’s harder to score cleanly, and you need to work fast.

The High-Altitude Sweet Spot: At 7,000 feet, the answer is somewhere in between. After that 1-hour morning proof, your dough should still feel cool to the touch – noticeably cooler than your hand, but not refrigerator-cold. This gives you clean scoring from slightly cool dough and good oven spring from active fermentation.

Here’s why this matters at altitude: if your dough is ice cold when it hits the oven, the center won’t have enough time to spring before the outer crust sets. At 7,000 feet, water boils at a lower temperature and heat transfers differently. The exterior of your loaf sets faster than at sea level, so you need interior fermentation active enough to push outward before the window closes.

On the flip side, if your dough is fully room temperature, it might be too relaxed and could spread rather than spring up. At altitude where dough already ferments faster, you’re walking a finer line between under and over-proofed.

How to Tell When It’s Ready: Your dough should pass the poke test (slow spring-back with slight indentation), and when you pick up the banneton, it should jiggle slightly but still hold its shape. This is your scoring window. Work quickly, get it scored, and get it in the oven while it’s still in that perfect temperature zone.

Baking · Heat and Steam

One hour before baking, preheat your Dutch oven to 475°F. When your dough is ready, dust it with rice flour and invert it onto parchment paper.

Your dough should still feel cool from the fridge. Score one clean expansion line from top to bottom at a 45-degree angle, about ½ inch deep. Work with confidence – hesitating or re-scoring the same line can deflate the dough. One smooth cut and you’re done.

Slide the dough onto your preheated baking steel on parchment paper and bake at 475°F for 20 minutes. Then, rotate the loaf, drop the temperature to 450°F, and continue baking for 15-20 minutes more until you get that deep mahogany crust and an internal temperature of 200-205°F.

The Wait · Let It Cool

Transfer to a cooling rack and wait at least an hour before slicing. The crumb is still setting, and cutting too early will give you a gummy mess.

When you finally cut into it, you should see an open, airy crumb with good structure – proof that your fermentation, shaping, and proofing all came together.

Final Thoughts

Is overnight sourdough more work than same-day? Not really – it’s just spread out over a longer timeline. But the flavor difference is significant. That cold retard develops complexity you can’t get any other way.

Once you dial in this recipe at altitude, it becomes your go-to. The one you make when you want bread that actually tastes like something.

Now get your starter ready and make some bread.