Zwiebelbrot (Sourdough Onion Bread) – Recipe & Guide

Savory sourdough onion bread with caramelized onions and a crisp crust. Practical schedule, troubleshooting and science-backed tips for consistent results.

At a Glance

Difficulty
medium
Active Time
45 minutes (excluding fermentation and cooling)
Total Time
20-26 hours (depends on proofing choices)
Yield
1 loaf (900-1000g)

Zwiebelbrot is a savory sourdough loaf combining caramelized onions, a chewy crumb and a crisp crust. Long fermentation develops sweetness and improves digestibility; onion addition contributes moisture and flavor while requiring small adjustments to hydration and fermentation management[1][2].

✓ Caramelized onion flavor throughout ✓ Flexible schedule (overnight options) ✓ Uses stretch-and-folds instead of intensive kneading

Not suitable if:

Ingredients

Weigh all ingredients on a kitchen scale. For savory breads, ingredient weights and hydration control are important for crumb and oven spring[1].

Ingredient Amount % Note
Bread flour 420g 84% strong flour for structure
Whole wheat flour 80g 16% adds flavor and color
Water 330g 66% lukewarm (20-24°C); adjust slightly if onions are wetter
Active sourdough starter 120g 24% fed and active (bubbly, 4-8 hours after feed depending on temp)
Salt 10g 2% adds taste and strengthens gluten
Caramelized onions 220g (approx. 2 medium onions before cooking) 44% cook down to concentrated, drain excess oil or butter
Olive oil 10g 2% for cooking onions; excess removed before mixing

Schedule

Weekend Version

Gentle daytime schedule with room-temp bulk

Day 1 morning - 9am Feed starter so it's active by afternoon
Day 1 afternoon - 3pm Caramelize onions, cool and drain excess oil (30-40 min)
Day 1 afternoon - 4pm Autolyse: mix flours and water, rest 30 min (30 min)
Day 1 late afternoon - 4:30pm Add starter and salt, incorporate onions and perform stretch-and-folds (15-20 min)
Day 1 4:50pm - 9pm Bulk fermentation at room temp with folds every 30-45 min for first 2 hours
Day 1 9pm Shape and place in [banneton](https://amzn.to/4sNHBYO) for final proof (10 min)
Day 1 9pm - Day 2 11am Final proof in fridge (10-14 hours) for better flavor and handling
Day 2 11:30am Bake (50-60 min)

Weekday Version

Evening mix, morning bake

Evening 8pm Caramelize onions and cool
Evening 8:30pm Mix dough and perform initial folds (20 min)
Evening 9pm Shape and place in banneton, refrigerate overnight
Next morning 7am Preheat oven with [Dutch oven](https://amzn.to/4sVhKhN) (30-45 min)
Next morning 8am Bake (50-60 min)

💡 Tips

  • If dough ferments faster than expected, move to fridge to slow activity[1].
  • Caramelized onions add moisture—if dough is noticeably loose, rest 15-30 min before shaping to let flour hydrate fully[2].

Step by Step

1

Prepare caramelized onions

Slice onions thinly. Cook in a stainless or non-reactive pan with a little olive oil (or butter) over medium-low heat until deeply golden and reduced (~30–40 min). Drain off any excess fat and cool to room temperature. Well-caramelized, concentrated onions add flavor without making the dough soggy[2].

✓ Visual check: Deep amber color, sticky but not watery
⚠️ Common mistake: Rushing with high heat → burnt onions and sharp flavor

⏱ 30-40 minutes

2

Autolyse and mix

Combine flours and water in a large mixing bowl. Rest 30 min (autolyse). Add active starter and salt, mix with a dough scraper or dough whisk until incorporated. Dough should feel tacky but cohesive.

✓ Visual check: No dry flour spots; dough gathers into a mass
⚠️ Common mistake: Adding salt during autolyse → can inhibit enzyme activity

⏱ 10 minutes + 30 min autolyse

3

Incorporate onions and bulk ferment

Add cooled onions and fold them into the dough using wet hands or a dough scraper. Perform 3-4 sets of stretch-and-folds at 30–45 min intervals during first 2–3 hours to build structure. Cover the dough between folds[1].

✓ Visual check: Onions evenly distributed; dough gains strength and slight sheen
💡 If onions are very wet, place them on a paper towel to absorb excess moisture before adding

⏱ 2-4 hours (depending on temperature)

4

Pre-shape and bench rest

Turn dough onto a lightly floured surface. Pre-shape into a round/oblong and rest 20–30 minutes under a bowl or towel to relax gluten before final shaping.

✓ Visual check: Dough feels relaxed and easier to shape

⏱ 20-30 minutes

5

Shape and final proof

Shape into desired loaf (batard or boule). Place seam-side up in a floured banneton. Final proof at room temp 1.5–2 hours or refrigerate 10–14 hours for better flavor and handling[1].

✓ Visual check: Loaf holds shape, slightly risen

⏱ 1.5–14 hours (depending on chosen method)

6

Bake

Preheat oven to 250°C/480°F with a Dutch oven inside for 30–45 min. Turn loaf onto parchment paper, score with a bread lame, and place into preheated Dutch oven. Bake covered 15–20 min, then remove lid and reduce to 200°C/400°F for 25–35 min until crust is deep brown. Internal temperature should reach 96–98°C (205–208°F), check with an instant-read thermometer[1][2].

✓ Visual check: Deep mahogany crust; hollow sound when tapped

⏱ 45–60 minutes

7

Cool

Remove from oven using oven mitts and cool on a rack for at least 2 hours before slicing. Cooling completes starch gelatinization and prevents gummy crumb[1].

✓ Visual check: Loaf is cool to the touch and crumb is set

⏱ 2+ hours

Tips & Variations

Variations

Cheese and onion

Add 100g grated aged cheddar folded in with onions

→ Savory richness and melty pockets

Herb version

Add 1 tbsp chopped fresh thyme or rosemary with onions

→ Fresh aromatic note

Caramelized shallots

Replace onions with shallots for a sweeter, more delicate flavor

→ More subtle sweetness

Pro Tips

  • 💡 Control onion moisture: excess will weaken gluten—pat onions dry after cooking and drain well[2].
  • 💡 Use a dough scraper to help fold onions in without tearing dough.
  • 💡 Allow a cold final proof for cleaner scoring and improved oven spring[1].
  • 💡 Slice the loaf the next day with a serrated bread knife to retain crumb texture.

Common Issues

Common problems with onion sourdough and how to fix them:

Storage

Room temperature in bread bag/box

4-6 days

Keep cut side down to reduce crust drying

Kitchen towel

3-4 days

Use breathable linen to avoid trapping moisture

Freezing

3 months

Slice before freezing; toast or warm slices from frozen

⚠️ Avoid refrigeration—starch retrogradation accelerates staling in the fridge[1].

Sources

  1. [1]
    The Perfect LoafThe Perfect LoafLink
  2. [2]
    PlötzblogPlötzblogLink