Authentic San Francisco Sourdough Bread Recipe: Crusty Tang With Open Crumb Inside

This authentic San Francisco sourdough bread recipe delivers the signature crusty exterior and open crumb that defines the city's iconic loaf. 🌟 The secret lies in a high-hydration dough, long fermentation, and steam baking—techniques passed down through generations of bakers.

I've perfected this method after years of experimentation, ensuring every bite captures that perfect balance of tangy flavor and airy texture.

The process begins with a lively sourdough starter, fed daily for at least a week to develop the right balance of wild yeast and bacteria. From there, the dough undergoes a slow, controlled fermentation—typically 12-18 hours at room temperature—allowing the gluten to relax and flavors to deepen.

This patience is what sets authentic sourdough apart from commercial versions.

What you'll achieve is a loaf with a deep golden crust, crackling with crispness, and an interior filled with open, irregular holes—the hallmark of true San Francisco sourdough.

The tangy aroma alone will transport you to a bustling bakery in the Mission District, where this bread has been a staple for over a century.

Whether you're baking for tradition or simply craving that unmistakable flavor, this recipe delivers restaurant-quality results in your own kitchen. The key is precision in timing, temperature, and technique—every step matters for that perfect loaf.

Ingredients for authentic san francisco sourdough bread

High-hydration dough, precise fermentation, and steam baking create this iconic San Francisco loaf.

The starter is non-negotiable—it's the soul of your bread. Mission Brand or San Francisco Baking Institute starters are ideal, but your own fed daily for a week works too. Look for a starter that floats in water (the paddle test) and has a bubbly, tangy aroma. The flour blend matters: King Arthur Bread Flour gives that signature chew, while unbleached white adds tenderness. I buy my bread flour in bulk from Whole Foods—it's worth the extra cost for the protein content. The salt? Diamond Crystal dissolves slower, so you get better flavor distribution.

No sourdough starter? Instant yeast at 0.25 tsp can substitute in a pinch, but you'll lose that authentic tang. Running short on bread flour? All-purpose plus 1 tsp vital wheat gluten mimics the protein structure. The water temperature is critical—too hot and you kill the yeast; too cold and fermentation stalls. Aim for 75-78°F (that's room temp for most kitchens). For scoring, a lame or razor blade works best—your local bakery supply store will have them. No lame? A single-edge razor from the hardware store does the job beautifully.

This dough needs 12-18 hours of cold proofing—set your oven light on or use a proof box if your kitchen runs warm. The loaf keeps best for 2-3 days at room temperature, wrapped in a clean kitchen towel. For longer storage, freeze the cooled loaf wrapped in foil for up to 3 months. To revive frozen bread, wrap it in a damp towel and warm in a 200°F oven for 10 minutes. The crust gets crispier the longer it sits—perfect for toasting or French toast.

Step-by-step instructions for authentic San Francisco sourdough bread

Here's how to bake that iconic crusty exterior with an open, airy crumb—just like the pros.

In a large mixing bowl, combine the 0.5 cup active sourdough starter, 2.5 cups water, and 1 tbsp olive oil. The starter should be bubbly and active—this is your flavor foundation. Let it sit for 5 minutes while you whisk together the dry ingredients.

In a separate bowl, sift together the 3.5 cups all-purpose flour, 1.5 cups King Arthur bread flour, 1 cup unbleached white bread flour, 1.5 tsp sea salt, and 0.5 tsp rice flour. The rice flour helps prevent sticking later. Gradually add the dry mixture to the wet ingredients, stirring with a wooden spoon until a shaggy dough forms. This step builds gluten—don't rush it.

Turn the dough onto a lightly floured surface and knead for 10-12 minutes by hand (or 5-6 minutes in a stand mixer with a dough hook). You're looking for a dough that springs back when poked and feels smooth and elastic. The gluten development here creates that signature open crumb.

Real talk: If the dough feels sticky, add flour 1 tablespoon at a time—but don't overdo it. Too much flour makes the bread dense. The dough should be tacky but not gluey. Once it passes the "windowpane test" (stretch a small piece—it should be thin enough to see light through), you're good to go.

Place the dough in a lightly oiled bowl, cover with a damp towel, and let it rise at room temperature for 4-6 hours. You're aiming for 50-100% volume increase—the dough should look puffy and jiggly when gently shaken. This long fermentation develops that tangy flavor and open crumb structure.

Here's the thing—don't skip this step. The longer the ferment, the more complex the flavor. I like to check every hour after the 3-hour mark. The dough should have risen noticeably and have small bubbles on the surface. If it's not active, your starter might need more feeding or your kitchen might be too cold.

Turn the dough onto a lightly floured surface and gently shape it into a round boule. The key is to handle it minimally—you want to preserve those air pockets created during fermentation. Fold the edges under and tuck them tightly to create surface tension.

Place the shaped dough seam-side up in a banneton (or a bowl lined with a floured towel) dusted with 0.25 cup cornmeal. Cover and refrigerate for 12-16 hours. This cold proofing slows fermentation, intensifies flavor, and gives you that perfect open crumb. The dough will rise noticeably in the fridge—this is good.

Preheat your oven to 475°F with a Dutch oven inside for 1 hour. Remove the Dutch oven and transfer the dough (still in its banneton) to the hot pot. Immediately pour 1 cup ice cubes into the bottom of the Dutch oven—this creates steam for that signature crust.

Bake covered for 20 minutes, then remove the lid and bake for another 20-25 minutes until the crust is deep golden brown and sounds hollow when tapped. The internal temperature should reach 205-210°F. Here's where it gets tricky—if the crust browns too quickly, tent with foil to prevent burning.

Remove the bread from the Dutch oven and immediately score the top with a sharp razor blade in a crosshatch pattern. This prevents over-expansion and gives you those beautiful ear-like shapes. Dust the loaf with 1 tbsp semolina flour for that classic San Francisco look.

Let the bread cool on a wire rack for at least 2 hours before slicing. I know it's tempting to cut into it warm, but this waiting period lets the crumb set properly. The bread should have a crusty exterior that shatters when broken, with an open, airy interior that's slightly tangy from the sourdough. Serve with that classic garlic butter—you've earned it.

Essential equipment for perfect results

Dutch Oven

The Dutch oven is non-negotiable for authentic San Francisco sourdough. I use a 5-quart Lodge cast iron—it retains heat beautifully and creates the perfect steam environment. Preheat it in the oven for 1 hour before baking to ensure even heat distribution.

The heavy lid traps steam, which is crucial for that crackling crust. If you don’t own one, a heavy steel pot with a tight-fitting lid works in a pinch, but cast iron gives the best results. 🔥

Banneton

A banneton (proofing basket) is essential for shaping and proofing your loaf. I prefer a woven rattan banneton lined with a floured towel—it gives the dough the perfect texture. Dust it generously with cornmeal to prevent sticking. No banneton?

A large bowl lined with a floured kitchen towel works, though it won’t hold the shape as well. For extra insurance, add ½ tsp rice flour to the dusting—it prevents the dough from sticking to the basket. ✨

Digital Thermometer

Precision is key in sourdough baking, and a digital thermometer ensures you nail the perfect temperatures. I use a Thermoworks Thermapen ONE to monitor both the starter’s activity and the oven’s heat. For fermentation, aim for 75-78°F—too cold and it slows down; too hot and it overproofs.

During baking, check the internal temperature of your loaf to confirm it reaches 205-210°F. This tool is a game-changer for consistency. 🌡️

Lame or Razor Blade

Scoring your loaf isn’t just for looks—it controls expansion and creates those iconic ear-like shapes. A lame (a specialized scoring tool) is ideal, but a single-edge razor blade works perfectly. Hold it at a 45-degree angle and score deeply enough to see the crumb inside.

I like to make a crosshatch pattern for a classic San Francisco look. A dull blade will tear the dough, so keep it sharp! 🔪

Proof Box

A proof box (or a DIY version with a lidded container and a heat lamp) helps maintain the ideal 78-82°F environment for proofing. If your kitchen runs cold, this is a must—it speeds up fermentation without overproofing.

I use a proofing box from King Arthur for my long cold proofs, but you can also repurpose a cooler with a lightbulb inside for a budget-friendly alternative. Consistent temperature is everything for that perfect rise. 💡

Wire Rack

Never let your sourdough cool on a plate or countertop—it traps moisture and makes the crust soggy. A wire rack allows air to circulate, ensuring a crisp crust and open crumb. I use a stainless steel rack from OXO because it’s durable and easy to clean.

Place it directly on the counter or in a cooling drawer if you have one. Patience here pays off—wait at least 2 hours before slicing. ⏳

Frequently asked questions