Soft Seeded Sourdough Sandwich Bread (5×13 Pan)

Once your sourdough starter is mature and active, the real fun begins: baking bread. This seeded sourdough sandwich loaf has become one of my favorite weekly bakes. It’s hearty, soft enough for sandwiches, slightly sweet, and packed with whole grains and seeds.

This recipe is designed specifically for a 5×13 bread pan, which creates a wide loaf perfect for toast and sandwiches.

The Finished Loaf

After dialing in the fermentation timing and ingredient ratios, this loaf came out exactly how I hoped. The crust developed a deep brown color with a natural split across the top — a sign of good oven spring.

Because this dough contains whole grains and seeds, the loaf spreads slightly wider instead of rising extremely tall. That actually creates the perfect sandwich shape.

Soft Seeded Sourdough Sandwich Loaf (5×13 Pan)

Dough Ingredients

• 200 g active sourdough starter
• 450 g bread flour
• 60 g whole wheat flour
• 40 g wheat germ
• 420 g warm water
• 35 g honey
• 15 g brown sugar
• 10 g salt
• 1 egg white
• 2 tbsp ground flax seed
• 2 tbsp chia seeds
• 1 tbsp whole flax seeds
• 15 g sunflower seeds
• 15 g pumpkin seeds
• 2 tbsp dry quinoa
• 1 tsp cinnamon (optional)

Reserved Flour

• 50 g bread flour (for dusting during mixing and shaping)

Instructions

1. Mix the Dough

In a large bowl combine the warm water, sourdough starter, honey, and brown sugar. Stir until the starter dissolves.

Add the bread flour, whole wheat flour, wheat germ, salt, egg white, seeds, quinoa, and cinnamon.

Mix until a shaggy dough forms.

2. Rest the Dough

Cover and allow the dough to rest for about 30 minutes. This helps the flour hydrate and improves gluten development.

3. Knead or Stretch

Knead the dough for about 8–10 minutes or perform stretch-and-folds every 20 minutes for an hour.

4. Bulk Fermentation

Allow the dough to ferment at room temperature for about 4–6 hours, until it has noticeably risen and feels airy.

During fermentation I lightly dust the dough with some of the reserved flour to prevent sticking and make it easier to handle.

5. Shape

Shape the dough into a tight loaf and place it seam side down into a lightly greased 5×13 bread pan.

6. Final Rise

Allow the dough to rise until it reaches about 1 inch above the rim of the pan.

7. Bake

Preheat the oven to 375°F (190°C).

Bake for 25-40 minutes until the crust is deep golden brown.

Use a digital thermometer to check the center of the loaf. The internal temperature should reach 195–200°F.

8. Cool

Remove the loaf from the pan and place it on a cooling rack.

I place a clean towel under the rack and loosely drape another towel over the top while the bread cools. This keeps the crust from becoming too hard while still allowing the bread to breathe.

Allow the loaf to cool for at least 1 hour before slicing.

Weight Watchers Friendly

This bread also works well for a Weight Watchers style eating plan.

• 15 slices: 2 points per slice
• 30 slices: 1 point per slice

Because the loaf is large and filling, slicing it thinner creates a great low-point option for toast and sandwiches.

Serving Ideas

This bread is delicious on its own, but one of my favorite ways to enjoy it is lightly toasted with apple butter.

The mild sweetness from the honey and brown sugar pairs really well with the warm spices in apple butter, while the seeds give each bite great texture.

It’s also great for:

• Avocado toast
• Peanut butter toast
• Grilled cheese sandwiches
• Turkey sandwiches
• Breakfast toast with honey

Final Thoughts

This loaf has become one of my favorite weekly bakes. It’s hearty, flavorful, easy to slice for sandwiches, and flexible enough to fit into a healthy eating plan.

There’s something incredibly satisfying about baking your own bread — especially when the whole house smells amazing while it cools on the rack.