America's Test Kitchen Sourdough Bread Recipe: Tangy, Airy Loaf Without the Guilt

America's Test Kitchen sourdough bread recipe delivers the perfect balance of tangy flavor, open crumb, and crisp crust—without the frustration of failed starters or dense loaves. This method transforms simple ingredients into a restaurant-quality loaf that's foolproof for beginners and refined for experienced bakers alike.

The key lies in precise fermentation times and dough handling techniques that create that signature airy texture we all crave.

What sets this recipe apart is its attention to detail at every stage, from building your starter to scoring the final loaf.

We'll guide you through creating a reliable starter from scratch (no prior experience needed) and walk you through the entire process—dough preparation, bulk fermentation, shaping, proofing, and baking in a Dutch oven for that iconic oven spring.

The result is a loaf with a deep, complex tang and a crisp crust that shatters perfectly.

This isn't just another sourdough recipe—it's a complete system that works reliably in your home kitchen. We've tested and refined each step to eliminate common pitfalls like overproofing or underbaked centers, ensuring you get a beautiful loaf every time.

The recipe includes troubleshooting tips for common issues and variations for different flour types, so you can customize it to your preferences.

Whether you're making your first loaf or perfecting your technique, this method gives you professional results with the confidence of knowing exactly why each step matters. Let's get started on creating your perfect sourdough loaf—one that'll have you reaching for the bread knife instead of store-bought every time.

Ingredients for america's test kitchen sourdough bread

Fourteen simple ingredients transform into a restaurant-quality sourdough loaf with perfect tang and crisp crust.

The flours are non-negotiable here. King Arthur Bread Flour gives that signature open crumb, while unbleached all-purpose keeps things manageable for beginners. Grab these at King Arthur Flour's website or any well-stocked grocery store—Whole Foods or Trader Joe's carry both. For the starter, you'll need an active, bubbly culture—if yours is sluggish, feed it daily for 2-3 days before baking. The Diamond Crystal kosher salt is crucial; it dissolves evenly without leaving gritty bits. If you're in a pinch, regular table salt works but reduce to 1 tsp.

No bread flour? Substitute all-purpose plus 1 tbsp vital wheat gluten—it mimics the protein structure. Milk can be swapped for water (just reduce by 2 tbsp), but the fat content helps with oven spring. For the olive oil, avocado oil works too, though it lacks the fruity notes. The yeast is optional if you're using a strong starter—skip it entirely if your starter is at peak activity. Cornmeal is traditional, but semolina or rice flour work just as well for dusting. And if your starter isn't ready? Use 1 tsp active dry yeast instead—just know the flavor will be slightly less complex.

This dough keeps for 24 hours in the fridge if you need to slow fermentation. For scoring, use a razor blade or sharp lame—a single-edge safety razor works in a pinch. The loaf is best eaten within 3 days for peak crust crispness, though it'll stay fresh wrapped in a towel for 5-7 days. Freeze slices for up to 3 months—toast straight from frozen for maximum crunch. Leftovers? Toss in a bread box or paper bag to maintain moisture.

Step-by-step instructions for america's test kitchen sourdough bread

Here's the method that delivers a consistently airy, tangy loaf every time—no guesswork involved.

In a large mixing bowl, combine the 5 cups unbleached all-purpose flour, 1 cup king arthur bread flour, 0.5 cup granulated white sugar, 0.25 tsp instant yeast, and 1.5 tsp diamond crystal kosher salt. Whisk gently to aerate the dry ingredients and create a uniform base. This initial blend ensures even distribution of flavor and structure throughout the dough.

Next, add 0.5 cup whole milk and 0.25 cup extra-virgin olive oil to the dry mixture. Using a wooden spoon or dough whisk, gradually incorporate these wet ingredients until you achieve a shaggy, crumbly texture. You're aiming for a consistency similar to wet sand—this stage is crucial for proper gluten development later.

Gradually add 2.5 cups water to the bowl while mixing continuously. The dough will begin to come together, but it may still appear sticky and uneven. At this point, incorporate the 0.5 cup active sourdough starter—this is where the magic begins. The starter introduces beneficial bacteria and yeasts that create that signature tangy flavor.

Once all ingredients are combined, use a dough scraper to gather the dough into a cohesive mass. Wet your hands slightly to prevent sticking, then knead the dough on a clean surface for 8-10 minutes. You're looking for smooth, elastic dough that springs back slowly when poked. The gluten structure is forming now, which will give your bread its signature open crumb and chewy texture.

Shape the dough into a loose ball and place it in a lightly oiled bowl. Cover the bowl with a damp kitchen towel or plastic wrap and let it rest at room temperature (70-75°F) for 4-6 hours. During this bulk fermentation, the dough will roughly double in size as the yeast and sourdough starter work their magic. You'll notice bubbles forming on the surface and throughout the dough—a clear sign fermentation is active.

I recommend performing stretch-and-folds every 30 minutes during the first 2 hours of bulk fermentation. To do this, wet your hands, grab one side of the dough, stretch it upward, and fold it over itself. Rotate the bowl and repeat this process on all sides. This technique strengthens the gluten structure and promotes even fermentation, resulting in a more open crumb structure.

After the bulk fermentation, gently shape the dough into a round loaf. Use a bench scraper to divide the dough into four equal sections, then roll each section into a log shape. Stack these logs vertically in a greased pullman pan or Dutch oven, seam-side down. This shaping technique creates the classic sourdough boules with their signature open crumb.

Cover the dough again and refrigerate overnight (12-16 hours). Cold fermentation slows yeast activity, allowing flavors to develop more deeply. The dough will rise slowly in the fridge, and the cold temperature helps create that perfect balance of tang and sweetness. When you're ready to bake, remove the dough from the fridge and let it come to room temperature for 1 hour before baking.

Preheat your oven to 450°F with a Dutch oven inside for 45 minutes. This long preheating ensures even heat distribution and proper steam generation. Carefully transfer the dough (still in its pullman pan) to the hot Dutch oven. Dust the top of the dough with 1 tbsp rice flour—this will create steam during baking, promoting oven spring and a crisp crust.

Bake the bread covered for 30 minutes, then remove the lid and bake uncovered for an additional 15-20 minutes until the crust is deep golden brown and the internal temperature reaches 205-210°F. The bread should sound hollow when tapped on the bottom. If the crust browns too quickly, tent the bread with aluminum foil to prevent over-browning while it continues to bake.

Remove the bread from the Dutch oven and transfer it to a wire rack. Let it cool completely for at least 2 hours before slicing. This resting period allows the gluten to relax and the crumb to set properly. If you can't resist, slice a thick piece and toast it—you'll be rewarded with that perfect balance of crisp crust and airy interior.

For best results, store any leftovers in an airtight container at room temperature for up to 3 days. You can also freeze slices for up to 3 months—simply toast from frozen for a fresh-baked experience whenever you crave it. This method consistently delivers a sourdough loaf with an open crumb, tangy flavor, and perfect oven spring that rivals any artisanal bakery.

Common mistakes when making perfect results

Overproofed Dough

One of the most common mistakes is letting your dough ferment too long, which leads to a collapsed loaf with weak structure. I've seen this happen when bakers skip the stretch-and-folds during bulk fermentation or don't check dough temperature (78-80°F is ideal).

Use the poke test: gently press your finger into the dough—if it springs back slowly (like Jell-O), it's ready. If it springs back immediately, it needs more time. If it leaves an indent, it's overproofed. 🌡️

Underdeveloped Gluten

Dough that feels gummy or doesn't hold its shape often means the gluten wasn't properly developed. The intro mentioned kneading for 8-10 minutes, but many bakers rush this step.

Try the windowpane test: stretch a small piece of dough between your fingers—if it's thin enough to see light through (like a windowpane), your gluten is ready. If it tears easily, knead another 2-3 minutes.

Skipping the Dutch Oven

Baking without a Dutch oven often results in a dense loaf with poor oven spring. The steam from the Dutch oven creates that signature open crumb. If you don't have one, use a heavy oven-safe pot with a lid or even a baking stone with steam pans.

Preheat everything for 45 minutes at 450°F—this mimics the steam chamber effect. Without it, you'll lose that professional bakery texture.

Incorrect Starter Strength

Using a sluggish starter is a surefire way to weak fermentation and poor flavor. Your starter should float in water (like a pancake) when it's ready. If it sinks, feed it daily for 2-3 days with equal parts flour and water.

I've found that 100% hydration starters work best for this recipe—thicker starters can make the dough too stiff. For beginners, maintain your starter at room temperature and feed it every 12 hours.

Overmixing After Shaping

After shaping, avoid excessive handling which deflates the dough and weakens the gluten structure. When rolling logs for your boule, work quickly and gently. The dough should feel firm but yield slightly when pressed.

If you notice the dough sticking excessively, dust your surface with rice flour (not all-purpose) to prevent gluten development from the extra flour. This maintains the delicate structure needed for that perfect open crumb.

Baking Temperature Fluctuations

Opening the oven door during baking can cause dramatic temperature drops, leading to uneven baking and potential collapse. Once you remove the Dutch oven lid after 30 minutes, avoid peeking again until the final 15-20 minutes.

Use an oven thermometer to verify your oven's accuracy—many home ovens run 25-50°F hotter than set. If your bread browns too quickly, tent it with foil to protect the crust while maintaining internal temperature. 🔥

Frequently asked questions