How to Make Potato Sourdough Bread with Leeks

Last updated on April 14th, 2025 at 01:13 pm

This potato sourdough with leeks is a savoury, rustic loaf that brings together the best of both worlds: the soft, creamy texture of potato sourdough bread and the gentle sweetness of sautéed leeks. Inspired by the classic comfort of leek and potato soup, this loaf takes those familiar, cozy flavours and transforms them into artisan bread with a chewy, open crumb and blistered golden crust. The roasted potatoes add moisture and a hint of sweetness, while the leeks offer savoury depth that lingers in every bite.

Potato Sourdough Bread with Leeks – Introduction & Inspiration

This loaf is rooted in memory. I first started experimenting with potato sourdough nearly two decades ago while baking at Rundles Restaurant in Stratford, Ontario. At the time, we used a yeasted biga for structure and subtle acidity, incorporating roasted potatoes into a soft, flavorful dough. It was rustic, yet refined—a loaf we served warm with cultured butter or alongside soup courses.

That formula stuck with me. Over the years, I’ve evolved it into something deeper: a naturally leavened sourdough, layered with the same potato richness but paired with sweet, mellow leeks—an ingredient that immediately called to mind the comforting flavour of leek and potato soup. This sourdough is my way of capturing that nostalgia in bread form.

Why This Potato Sourdough Loaf Works

This potato sourdough with leeks isn’t just a twist on a classic—it’s a fully realized loaf with its own personality. The roasted potatoes bring a soft, almost creamy crumb, while sautéed leeks thread gentle sweetness and umami throughout each slice. Every bite has contrast: the blistered crust, the tender interior, and the balance of savoury and sweet from the inclusions.

Folded in during bulk fermentation, the leeks and potatoes are evenly distributed, adding both flavour and visual texture. It’s a bread that feels comforting and elevated at the same time—perfect with butter, cheese, soup, or on its own, still warm from the oven.

The Inspiration Behind This Potato Sourdough Bread

The original potato sourdough I baked at Rundles was simple but memorable—pillowy crumb, deep flavour, and always a hit with guests. That formula used a yeasted preferment (biga) and roasted potatoes for richness. I still remember the way those loaves smelled when they came out of the oven.

This version takes everything I loved about that bread and gives it new life through natural fermentation. Adding leeks was instinctual—it’s one of the most comforting ingredients I know, and when paired with potato, it immediately brings to mind the classic leek and potato soup. That’s the soul of this bread: memory-driven, but evolved.

Why Potatoes in Sourdough?

Potatoes are a baker’s secret weapon. Their natural starches trap water, helping to boost hydration without making the dough sticky or hard to manage. The result is a softer crumb, a longer shelf life, and a tenderness you just can’t get with flour alone.

Roasting the potatoes concentrates their flavour and reduces excess moisture—so you’re adding depth without throwing off the dough’s balance. They also contribute natural sugars that help caramelize the crust, giving it a beautiful golden finish.

Why Use Leeks?

Leeks are one of the most underrated inclusions in sourdough. Milder and sweeter than onions, they blend beautifully into dough. They don’t overpower; instead, they mellow and melt into the crumb, adding savoury depth and just a touch of sweetness.

FLOUR SPECS

This potato sourdough uses a blend of strong bread flour, whole wheat flour, and a touch of rye flour—each chosen for its unique role in balancing structure, flavour, and fermentation.

• 76.3% Bread Flour (in the final dough)
  The high-protein bread flour provides the structure needed to support a high-hydration dough with inclusions like potatoes and leeks. It creates strength, elasticity, and an open crumb.
• 23.7% Whole Wheat Flour (in the final dough)
  Whole wheat flour adds flavour, minerals, and fermentation activity. It brings a rustic, nutty depth that pairs beautifully with the leeks and fresh dill.
• Rye Flour (in the levain only)
  A small percentage of rye is used in the levain to boost fermentation. Rye flour is rich in enzymes and ferments quickly, helping the levain develop strength and acidity even in small amounts. While it doesn’t appear in the final dough, its impact is noticeable in the overall flavour and fermentation profile.

Note: If you want to adjust the flour blend, you can easily substitute whole wheat for spelt or swap in more rye for a tangier loaf. Just keep in mind that higher whole grain percentages will change proofing time and dough strength.

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INGREDIENT SPECS

Potatoes

Roasted and roughly chopped or crushed potatoes are a key inclusion in this sourdough, contributing moisture, sweetness, and a tender crumb without making the dough overly soft or heavy. Roasting concentrates the flavour and dries the exterior slightly, which helps integrate them into the dough without introducing excess water. Yukon Gold or Russet potatoes work especially well due to their high starch content and creamy texture once roasted, but any starchy potato will do. The pieces are folded in during mixing, creating subtle pockets of flavour and texture throughout the loaf.

Leeks

Leeks bring a mild, sweet onion flavour that integrates beautifully into the dough. Unlike stronger alliums, leeks provide a gentle savoriness that complements the potatoes without overwhelming them. They soften easily during baking and distribute evenly throughout the crumb. Be sure to clean them thoroughly to remove any hidden grit, then slice and sauté until just tender before folding into the dough.

Optional Add-Ins

This sourdough potato formula is flexible and open to variation. Depending on your preference, you can incorporate:

• Fresh dill (used in this version) for brightness and balance
• Thyme or rosemary for an earthy, aromatic touch
• Grated hard cheeses like cheddar or Gruyère for richness and a salty bite
• Finely chopped chives or scallions as an alternative or addition to the leeks

Keep total inclusions around 30–35% of the dough weight to maintain structure and avoid a dense loaf.

POTATO SOURDOUGH WITH LEEKS SPECS

Yield	Two 900-gram loaves
Total Dough Weight	1800 grams
Pre-Fermented Flour	5.06%
Levain % in Final Dough	16%
Total Hydration	81.5 %
Total Inclusions (Potatoes & Leeks)	35%

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TOTAL FORMULA

Weight	Ingredient	Baker’s %
572 g	Bread Flour	76.3%
191 g	Whole Wheat	23.7%
651 g	Water	81%
41 g	Levain	5.1%
15 g	Salt	1.9%
153 g	Roasted and Crushed Potatoes	19%
114 g	Chopped Leeks	14.2%

The total formula reflects everything in the dough. This is the levain + the final dough.

POTATO SOURDOUGH DOUGH SCHEDULE

To help you bake this at home, I have created a suggested timeline for each process step. This schedule is meant to be a guideline but by no means do you have to stick to it. Feel free to adapt the recipe or timing to best fit your baking schedule.

MIX THE LEVAIN – 9:00 am

Weight	Ingredient	Bakers %
41 grams	Bread Flour	100%
41 grams	Water at 28°C / 82.4°F	100%
41 grams	Levain	100%

Mix all the ingredients until well combined. This build should take about 4-5 hours if you use a water temperature of 28°C/82.4°F to reach full maturity.

Note: This recipe uses a small, mature levain to bring balanced fermentation and structure to the final dough. Whether you build it the morning of or use an overnight levain, the most important thing is that it’s ripe and active when added to the mix. If you’re still getting comfortable with levain timing, inoculation percentages, or temperature control, check out my in-depth sourdough starter guide—a resource built from over 15 years of baking and starter maintenance.

Fermentolyse – 1:00 pm

This step combines the benefits of an autolyse with an early levain addition. By mixing the flour, water, and levain together and letting it rest, the dough begins developing gluten while also kickstarting fermentation. It’s a great way to simplify the process without sacrificing structure or flavour.

I especially like fermentolyse for doughs with inclusions or higher hydration—less mixing later, and a smoother overall feel in the dough.

Fermentolyse Mix:

Weight	Ingredient	Baker’s %
572 g	Bread Flour	75.0%
191 g	Whole Wheat Flour	25.0%
549 g	Water (Water 1)	72.0%
122 g	Levain	16%

1. Combine the flour, Water 1, and mature levain in a large bowl.
2. Mix until no dry bits remain and the dough is fully hydrated.
3. Cover and let rest at room temperature for 1 hour.

After the fermentolyse, the dough will feel more elastic and cohesive—ready for salt and the second water addition.

Roast the Potatoes & Prep the Leeks – After Autolyse

While the dough is resting during autolyse, roast the potatoes so they’re ready to mix in during the next stage.

Roasting the Potatoes:

1. Scrub and rinse your potatoes (Yukon Gold or Russet work best).
2. Leave the skins on or peel if preferred.
3. Roast at 425°F (220°C) for 45–60 minutes, or until fork-tender and lightly blistered.
4. Let cool until you can handle them comfortably, then crush them roughly with a fork or your hands. You’re looking for small chunks—not a mash.

This step concentrates the flavour and removes excess moisture, helping the potatoes integrate better into the dough.

Prepping the Leeks:

At this stage, you can either leave them raw or lightly sauté until just tender, depending on your preferred texture and flavour intensity. I usually leave them raw to save time as they will steam and cook inside the dough.

1. Slice leeks lengthwise and rinse well to remove any dirt or grit hidden between layers.
2. Slice thinly into half-moons.

MIX THE DOUGH – 2:00 pm

After the fermentolyse, the dough will already feel elastic and slightly fermented. At this stage, we’ll add the salt and remaining water (Water 2), and begin building strength in the dough.

Mixing Additions:

Weight	Ingredient	Baker’s %
15g	Salt	1.9%
61 g	Water (Water 2)	13.4%
153 g	Roasted Potatoes	19.0%
114 g	Chopped Leeks	14.2%

1. Add salt directly to the dough:
   Sprinkle the salt evenly over the surface of the dough.
   
2. Pour Water 2 over the salt:
   Gently pour the remaining water directly on top of the salt. This helps dissolve it into the dough more easily.
   
3. Mix by hand:
   Use your hands to squeeze, fold, and incorporate the water and salt into the dough. At first, the dough may feel slack and slippery but continue mixing for 5–10 minutes. As the water absorbs, the dough will begin to strengthen and tighten.
   
4. Check the dough feel:
   The dough should be cohesive, hydrated, and slightly elastic. It doesn’t need to pass the windowpane test yet—bulk fermentation will continue to build strength.
   
5. Transfer the dough:
   Move the dough to a clean, lightly oiled container. Cover and let rest before starting the bulk fermentation.

Bulk Fermentation – 2:30 to 5:30 pm

Bulk ferment the dough for 3 hours at room temperature (ideally between 25–28°C / 77–82°F). This stage builds dough strength and allows fermentation to begin developing flavour and structure.

If your kitchen runs cool, place the dough in a warm spot, covered, to maintain consistent fermentation. If you’re in a warm environment, avoid direct heat—an over-proofed dough will be more difficult to shape later.

You’ll perform two folds during bulk: one standard coil or stretch-and-fold, followed by a lamination fold to add inclusions.

First Fold – 3:00 pm

1. Uncover the dough and gently loosen it from the sides of the container using a wet dough scraper.
2. With damp hands, grab one side of the dough, stretch it up gently (without tearing), and fold it over toward the center.
3. Rotate the bowl a quarter turn and repeat on all four sides.
4. Flip the dough seam-side down, cover, and rest.

This fold helps strengthen the dough early in bulk and builds internal structure.

Second Fold (Lamination with Inclusions) – 4:00 pm

Instead of a standard fold, this step incorporates the roasted potatoes and leeks using a lamination technique.

1. Lightly wet your hands and the bench if needed to prevent sticking.
2. Gently turn the dough out onto the surface and carefully stretch it into a large rectangle.
3. Evenly distribute the inclusions over the surface:
   • Roasted and crushed potatoes
   • Leeks
   • Chopped dill or other add-ins (if using)
4. Fold the dough from one side over the center, then fold the other side on top (like a letter).
5. Fold the top and bottom toward the center to create a loose square.
6. Gently round it into a ball and return to the bowl, seam-side down. Cover and continue bulk fermentation.

This method ensures even distribution of the inclusions without overworking the dough or tearing the gluten.

DIVIDE AND PRE-SHAPE – 5:30 pm

After bulk fermentation, the dough should feel airy, soft, and well-structured. This step helps organize the gluten before the final shaping.

1. Gently turn the dough out onto a clean, unfloured work surface. If needed, lightly wet the bench and your hands to prevent sticking.
   
2. Use a bench knife to divide the dough into two equal portions (approximately 900g each).
   
3. Working one piece at a time, use your hands or a bench scraper to gently tuck and round the dough into a loose ball.
   
4. Place the rounds seam-side down on the bench, cover with a towel or inverted bowl, and let rest for 20–30 minutes.

FINAL SHAPE – 6:00 pm

Now that the dough has relaxed, it’s ready for the final shape. This step builds surface tension and structure, setting up the dough for a strong oven spring.

1. Gently flip each rested round seam-side up using a bench knife or your hands.
2. Place the dough onto a clean, unfloured surface (lightly dampen the bench or your hands if needed to reduce sticking).
3. Stretch the sides of the dough outward, then fold them back toward the center, slightly overlapping.
4. Grab the top middle of the dough, pull it down toward the bottom, and press to seal.
5. Starting at the top corners, stitch the loaf by folding the edges inward and working your way down, creating surface tension.
6. Flip the dough over so the seam is now down. Use your hands or bench knife to gently tighten the shape, tucking and rotating as needed.
7. Let the dough rest seam-side down for 5–10 minutes to relax.
8. Lightly flour the top, then invert and place seam-side up into a well-floured banneton.

Tip: If you’re new to shaping, watching a video of this technique can be really helpful. Shaping takes practice—don’t worry if it’s not perfect on the first try.

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FINAL FERMENTATION – 6:45 pm to the next morning

Once shaped and placed into bannetons, cover the loaves well and refrigerate overnight for a cold final proof. This extended fermentation slows down yeast activity while allowing the bacteria in the sourdough culture to develop a deeper, more complex flavour.

Place the covered bannetons in the fridge and let the dough ferment for 12–18 hours. It will continue to rise slowly and should be slightly puffed, relaxed, and hold a gentle indent when lightly pressed.

Note: You can bake the same day if needed, but the overnight cold proof consistently yields better flavour, structure, and crust.

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BAKING – 9:00 am

Preheat your oven with a Dutch oven inside to 500°F (260°C) for at least 45 minutes to 1 hour. A fully preheated Dutch oven is essential for getting maximum oven spring and a well-developed crust.

1. Remove one loaf from the fridge and gently invert it onto a square of parchment or directly into the Dutch oven, seam-side down.
2. Score the top using a lame or sharp blade. A simple slash down the center works well, but feel free to experiment with your own scoring patterns.
3. Optional: Lightly mist the inside of the Dutch oven with water before placing the lid on—this helps create extra steam and encourages better oven spring.
4. Place the Dutch oven back into the oven and immediately reduce the temperature to 480°F (248°C).
5. Bake covered for 20 minutes, then remove the lid and continue baking uncovered for another 20–25 minutes, or until the crust is deep golden brown.
6. Remove the loaf and transfer to a wire rack to cool.

Tip: For a more caramelized crust, bake slightly longer with the lid off. To check doneness, the internal temperature should be around 206°F (96.5°C).

Allow the bread to cool fully before slicing—this helps the crumb set and prevents gumminess.

POTATO AND LEEK SOURDOUGH: FINAL THOUGHTS

This Potato and Leek Sourdough is one of those loaves that feels both familiar and elevated—rooted in comfort, but refined through process. The soft, creamy texture from the roasted potatoes and the subtle sweetness of the leeks make this a standout loaf for fall and winter baking, but honestly, it’s one I’ll return to year-round.

Like many of my favourite breads, this recipe is also a great jumping-off point for experimentation. You can swap in caramelized onions, fresh herbs, or even try folding in aged cheese for a heartier, more savoury version. The lamination technique used to incorporate the inclusions gives you endless creative freedom without sacrificing structure.

If you enjoyed this bake, here are a few more sourdough inclusion recipes you might love:

• Fig and Olive Sourdough – A sweet-and-salty Mediterranean-inspired loaf
• Turmeric Sourdough – Bright, earthy, and perfect for pairing with spice
• Gouda and Herb Sourdough – Rich, savoury, and packed with flavour

Want to see how I shape, laminate, or score my loaves? Check out the visuals and tutorials on my YouTube channel for step-by-step videos.

How to Serve Potato Sourdough Bread

This Potato Sourdough with leeks is incredibly versatile at the table. Here are a few of my favorite ways to enjoy it:

• Toasted with salted butter – The soft, creamy crumb is made for butter. Go simple or add flaky sea salt and herbs.
• Grilled cheese – Use it for an ultra-savory Sourdough Grilled Cheese Sandwich layered with sharp cheddar or Gruyère. The leeks in the bread bring even more depth.
• With soft-boiled eggs – Slice into toast soldiers and serve alongside Soft-Boiled Duck Eggs for a comforting breakfast or brunch.
• With soups and stews – Naturally pairs with classics like potato-leek soup, creamy carrot, or French onion.
• As a side to roast chicken or braised meats – The mellow sweetness of the leeks balances richer, savoury dishes.
• On a cheese board – The roasted potato and leek combo adds rustic character to any board.

Whether you’re making it for brunch, dinner, or just a killer toast moment, this loaf holds up beautifully.

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