Acme Sourdough Bread Recipe: Cold-Proofed Fermentation for Tangy Depth

The Acme sourdough bread recipe delivers that signature tangy depth and open crumb structure you crave, using cold-proofed fermentation for maximum flavor development. This method transforms ordinary flour into artisanal loaves with a crisp crust and airy interior—exactly what separates homemade from store-bought.

The secret lies in patient fermentation and precise technique, which we'll break down step by step.

What makes this recipe stand out is the balance between traditional methods and modern adaptations. You'll maintain the wet dough and long fermentation that create authentic sourdough flavor, while incorporating cold-proofing to streamline your schedule without sacrificing quality.

This approach builds flavor gradually, resulting in bread that's both complex and consistent.

The result is a loaf with a golden, shatteringly crisp crust that gives way to an open, airy crumb filled with pockets of steam. Each slice offers that signature tangy depth from properly fermented dough, making this recipe perfect for sandwiches, toast, or simply enjoying with butter.

The technique is approachable yet professional, designed to build your confidence with sourdough.

Whether you're a beginner eager to master sourdough or an experienced baker refining your technique, this recipe provides clear guidance at every stage—from maintaining your starter to scoring the final loaf. Let's get started on creating bread that rivals your favorite bakery.

Ingredients for acme sourdough bread

Four cups flour plus a lively starter—this is your ticket to bakery-style sourdough at home.

The starter is non-negotiable here. It needs to be 100% hydration and actively bubbling—think of it as the soul of your bread. King Arthur or Breadsaker flours are my go-tos for that perfect balance of protein and structure, but any high-quality bread flour works. The sugar and yeast combo might seem small, but they're working together to kickstart fermentation while the sourdough does its magic. Salt? Diamond Crystal is my favorite—it dissolves perfectly and enhances flavor without overpowering. If you're using a different brand, taste the dough before shaping to adjust.

No bread flour? All-purpose plus 1 tbsp vital wheat gluten per cup gets you close. Running short on starter? Add 1 tsp extra yeast to compensate, but expect less tang. The olive oil can be swapped for melted butter (same amount) if you're feeling indulgent—just let it cool completely before mixing. For the water, room temperature is key. Too cold and fermentation stalls; too warm and it goes wild. 75°F is ideal, but if your kitchen runs hot, chill the water slightly. Pro tip: Use a thermometer to check—it makes a huge difference in consistency.

This dough needs patience. After bulk fermentation, you'll cold-proof it for 12-16 hours—this is where the magic happens. Wrap tightly in plastic and refrigerate. The ice water for cold-proofing might seem odd, but it's what keeps the dough stable overnight. Once baked, those loaves keep well at room temperature for 2-3 days in a bread box, or you can freeze slices for up to 3 months. For maximum freshness, bake only what you'll eat in 48 hours—nothing beats the aroma of a just-baked loaf.

Step-by-step instructions for Acme sourdough bread

Here's how to craft a loaf with that signature Acme tang and open crumb—no shortcuts, just science-backed technique.

In a large mixing bowl, combine the 0.5 cup Active Sourdough Starter, 4 cups Bread Flour, 1 cup Unbleached All-Purpose Flour, 0.5 tsp Granulated Sugar, and 0.25 tsp Instant Yeast. The high-protein bread flour will give your loaf that signature chew, while the all-purpose adds lightness. Create a well in the center and add the 0.25 cup Extra-Virgin Olive Oil and 2.5 cups Room-Temperature Water—the water should be 75°F for optimal hydration without overactivating the gluten.

Mix using a wooden spoon or dough whisk until a shaggy dough forms, then switch to your hands. Knead for 8-10 minutes until the dough becomes smooth and elastic, with a slightly sticky but not wet surface. You'll know it's ready when it springs back slowly when poked—this indicates proper gluten development. If it feels too dry, add 1 tablespoon of room-temperature water; if too sticky, add 1 tablespoon of flour. The dough should feel like a well-worn baseball, neither too firm nor too soft.

Lightly oil a large bowl and place the dough inside, covering it with a damp kitchen towel or plastic wrap. Let it ferment at 75°F for 4-5 hours, until it has nearly doubled in size and looks puffy with bubbles along the surface. Here's the thing—this isn't just about waiting. Every 30 minutes, perform a "poke test": gently press your finger into the dough. If it springs back slowly (like Jell-O), it's ready. If it bounces back quickly, give it more time.

Real talk: The room temperature matters more than the time. If your kitchen is cooler, extend fermentation by 30-60 minutes. If it's warmer, reduce time slightly. Over-fermenting leads to a dense loaf; under-fermenting means weak structure. You want that perfect balance where the dough is airy but still has structure to hold its shape during baking.

Transfer the dough to a clean surface and gently deflate it by pressing down with your knuckles. Shape it into a round boule by pulling the edges toward the center and tucking them under. Place the boule seam-side up in a lightly oiled bowl, cover again, and refrigerate for 12-16 hours. This cold-proofing step is non-negotiable—it develops deeper flavor through slow fermentation and prevents overproofing in the oven.

Here's where patience pays off. The cold slows yeast activity, allowing enzymes to break down starches and gluten to relax. When you take it out of the fridge, the dough should look puffy but not collapsed. If it's flat, it needs more time. If it's overly domed, it's been overproofed. The ideal texture is like a well-inflated balloon—firm but yielding when pressed gently.

Lightly dust a baking sheet with 0.25 cup Cornmeal and place the cold dough on it. Let it sit at room temperature for 1-2 hours until it rises slightly and feels springy to the touch. This final rise ensures the dough has enough lift for a good oven spring. Preheat your oven to 450°F with a Dutch oven inside for 45 minutes—this creates a steam chamber for that perfect crust.

Using a sharp razor blade or lame, score the dough in a crosshatch pattern (about ¼-inch deep). This isn't just for looks—it controls expansion and prevents cracks. The blade should glide through like butter; if it resists, your dough needs more fermentation. Immediately transfer the scored boule to the preheated Dutch oven and bake, covered, for 30 minutes. Then remove the lid and bake for another 15-20 minutes until the bread is deep golden brown and sounds hollow when tapped on the bottom.

Remove the bread from the oven and let it cool on a wire rack for at least 1 hour before slicing. I know it's tempting to cut into it warm, but resisting gives the gluten time to relax and the crumb to set properly. The internal temperature should drop to 100°F before you even think about slicing—this ensures clean cuts and maximum flavor.

When you finally slice into your loaf, you should see an open, irregular crumb with pockets of air—proof of proper fermentation. The crust should be crisp and shatterable, with a deep caramelized color. Each slice should have that signature Acme tang from the sourdough starter, balanced by a soft yet chewy texture. Store any leftovers in an airtight container, but honestly? This bread rarely lasts that long.

Creative variations of this dish

Sweet & Savory Twist

Add 1 tablespoon honey or 1 teaspoon maple syrup to the dough during mixing for a subtle sweetness that pairs beautifully with savory toppings. I love finishing baked loaves with a sprinkle of flaky sea salt and a drizzle of honey—trust me, it elevates everything.

For a more pronounced sweet flavor, replace ½ cup of water with ½ cup milk during mixing. 🍯

Seeded & Nutty Variations

Incorporate 2 tablespoons of seeds like sesame, sunflower, or pumpkin into the dough for added texture and nutrition. For a heartier loaf, fold in ½ cup chopped nuts (walnuts, almonds, or pecans) during the final kneading stage.

I recommend toasting the nuts first to enhance their flavor—just spread them on a baking sheet at 350°F for 5-7 minutes until fragrant.

Herb-Infused Loaves

Add fresh or dried herbs like rosemary, thyme, or oregano for an aromatic twist. I typically use 1 tablespoon finely chopped fresh herbs or 1 teaspoon dried herbs mixed into the dough during the final kneading.