Sourdough Onion Bread

This delicious sourdough onion bread is packed with caramelized onions and bursts with fresh thyme and tangy aromas. It features a soft and tender crumb, making it a perfect savory bread to accompany soups and stews. It also makes for a wonderful loaf to add to your holiday table!

This sourdough onion bread is so delicious and makes for such a fun twist to a classic rustic loaf. It is actually a household favorite: my husband can't stop eating it and regularly requests that I make more of it!

What makes it so special is how incredibly soft the crumb is and it is packed with lots of flavors, thanks to the chunks of buttery caramelized onions and the subtle touch of fresh thyme.

It makes for a yummy everyday bread that's pretty easy to whip up together but also, it is the perfect sourdough bread recipe when looking for something savory to accompany your soups, stews, or pasta meal. Its earthy and festive character also will make it a great addition to your Christmas or Thanksgiving table!

And fear not, this sourdough bread is just as easy to prepare as making a regular loaf of sourdough: all you have to do is caramelize the onion with the thyme in a pan until tender, sweet and nicely browned. Then, simply incorporate them within the sourdough dough while doing your series of stretches and folds. So simple!

Hope you give it a try and let me know how it turned out in the comments below! ❤️

Naturally fermented onion bread

This caramelized onion bread rises naturally through fermentation from wild yeast (and healthy bacteria) from a sourdough starter. There are no leavening agents and no commercial dry yeast in this recipe!

Making sourdough bread at home using slow fermentation involves more rising time and patience, but this also means a loaf of bread that:

• has more gut-friendly nutrients
• is lower on the glycemic index
• features an appetizing rustic presentation and earthy bite
• has a lot more complex flavors

Crafting your own sourdough bread also is very satisfying and rewarding, plus you save a lot of money making your own. Totally worth the extra effort and time!

If you are new to sourdough baking, then check out this guide on how to make your own sourdough starter from scratch to get you started.

Sourdough onion bread scheduling

Here is the schedule that I usually like to follow when baking sourdough bread. This is highly variable depending on the dough temperature, moisture in your house and the ambient temperature, so keep in mind that your schedule and timing might be different than what I suggest here. Also, depending on your personal routine or lifestyle, you might prefer to make your dough at a different time of the day.

Just as a reference, once done with my stretches and folds, my dough was about 76-78ºF (or 24-25ºC), so I let it rise to 50% of its height before shaping and starting the cold ferment overnight. In my case, the bulk fermentation took about 5-6 hours (starting time once the dough is mixed), but if your house is warmer or colder than mine, then your dough might be ready quicker or faster.

• 8 am: feed the starter
• 8h15 am: caramelize the onion (this can be done anytime in the morning)
• Noon: the starter is bubbly and has risen more than double its height, so I used it and I mixed the dough ingredients together
• 12h30-2h00: incorporate the onion + 3 series of stretches and folds
• 2h00: continue the bulk fermentation (bulk fermentation started at noon and ended at 5h00)
• 5h00: pre-shape + shape, then transfer in proofing basket for the overnight final cold proof
• 9h00 am the next morning: preheat the oven with the Dutch oven in for 30-60 minutes, score and bake

Also, as seen in this same-day sourdough bread recipe, you can do the final proof at room temperature to have this bread ready quicker.

What you will need

(more details on the ingredients with measurements down below in the recipe card)

Equipment:

• Dutch oven: I like to bake sourdough bread at home using a Dutch oven, but if you don't have one, then check out this guide on how to bake sourdough bread using the open-bake method.
• Dough whisk: helpful to mix the dough in the early stage, but not essential.
• Dough scraper and bench scraper: help with the manipulation and transfer of the dough.
• Scale: helps measure the ingredients more precisely, giving better results. You can easily find a small inexpensive scale online.
• Parchment paper: to help transfer the shaped dough to the Dutch oven.
• Scoring lame: for scoring the dough.

Ingredients:

• Onion: I used one large sweet onion (Vidalia), but you can also use 2 small yellow onion.
• Fresh thyme: or swap for rosemary.
• Olive oil or butter: to cook the onion.
• Sourdough starter: you will need a fed and very active starter to make this recipe.
• Water: use room temperature or warm-ish water to help activate the rising activity of the yeast.
• Bread flour: I highly recommend using bread flour for making this recipe (as opposed to all-purpose flour) as it is higher in protein and helps build a stronger gluten network. This is especially important when adding inclusions in your loaf!
• Whole wheat flour: there is a small amount of whole wheat flour for taste and texture, plus whole grains boost the fermentation of the bread.
• Salt

How to make sourdough onion bread

(detailed recipe down in the recipe card)

Prepare your starter

Feed your starter about 4-6 hours before you need it. You can use it to mix the dough once it is very bubbly and active. Usually, it is ready to use once it has risen at least twice its height in the jar.

Cook the onion

Warm up a large pan with some olive oil or butter, then add the chopped onion, fresh thyme, salt and black pepper. Cook on medium heat for about 15-20 minutes or more, until the onions are soft, browned and caramelized.

Once done, set aside to cool down.

Mix the dough

In a large mixing bowl, add the bubbly sourdough starter and warm water. Use a dough whisk to combine. Then, add the bread flour, whole wheat flour and salt. Keep stirring until combined and there are no dry spots of flour visible (this can take a few minutes). The dough will look shaggy at this point.

Cover well (I like using plastic wrap) and set aside to rest for 20-30 minutes.

Stretches and folds (+ incorporate the onion)

Transfer the caramelized onions over the dough and then, incorporate them while doing 3 series of stretches and folds.

Stretch and fold method: add the onions over the dough in the bowl, then grab the dough on the opposite side of the bowl in front of you, pull or stretch it up until it gets tight or you can no longer pull without breaking the dough. Then fold it back and press it over the dough in the middle. Rotate the bowl 90º, then repeat. Keep going around the bowl until the dough feels too tight to stretch. I usually do 4-5 stretches/folds per session. The onions will slowly mix within the dough as you go.

You can wet your hands if needed so the dough does not stick to your fingers.

Bulk fermentation

Once done with the stretches and folds, then cover well and place in a cozy spot for about 5-7 hours. The dough is done fermenting once puffy, looks lighter, jiggles in the bowl when shaking it and has risen in the bowl, although it won't necessarily double.

If you have a thermometer, you can measure the dough temperature to guide you on fermentation time. Try to keep your dough at about 78ºF (move it to a warm spot if needed) so the fermentation takes about 5 hours.

Pre-shape

Transfer the dough over a clean and lightly floured surface and then: grab the edges of the dough, pull on them and bring them back over the middle of the dough to roughly shape it into a ball. Flip the dough so the seam side is on the counter, cover and let it rest for 20 minutes.

Shape

Flip the dough so the smooth part is on the counter, then stretch into a square. Fold the top part over the middle of the dough, then fold each side as well. Grab the top part of the dough and roll towards you while tucking the dough into a ball until the seam side falls on the counter.

Use both your hands to drag the dough on the counter by pushing it toward you. Slightly rotate and repeat. Keep going until the top part is smooth and the ball looks tight.

Cold proof (overnight)

Generously add flour to a proofing basket, then transfer the dough to the basket with the seam side up. Cover and transfer in the fridge overnight or for 5-36 hours.

Bake

Transfer the Dutch oven to your oven and preheat to 450º for at least 30 minutes (or even better 60 min).

Then, take the proofed dough out of the oven, flip over a large piece of parchment paper and score. Transfer the dough in the preheated Dutch oven by pulling on the edges of the parchment paper and cover. Bake for 30 minutes, then remove the cover, turn down the heat to 410ºC and bake for 5-7 more minutes or until golden brown.

Cool down

Take the bread out of the Dutch oven and transfer it to a cooling rack. Let the bread completely cool down before slicing and enjoying.

Baking tips

• Make sure you have a fed, bubbly and active sourdough starter before you mix the dough ingredients together. Otherwise, the loaf won't ferment as well and the crumb might be dense and gummy.
• The bulk fermentation time is highly variable depending on the temperature. I had a dough of about 77-78ºF and my house was cozy, so I let it ferment for about 5-6 hours. If your dough is colder and/or your house is chilly, then you might need to ferment for longer.
• If you want to make this loaf all on the same day, then skip the cold ferment once shaped and let it rest in the proofing basket for about 2 hours before baking. I find that cold ferment gives a better oven spring and is also easier to score.

Variations

This is an easy savory bread recipe where you can play around with the ingredients to create different flavor profiles.

• Herbs: you can swap the fresh thyme for fresh rosemary or even fresh oregano if you prefer. Dry herbs won't give it as much flavor but use them if that's all you have.
• Sweetness: when caramelizing the onion, feel free to add a little sugar or maple syrup if you like them sweeter. Adding sugar can also speed up the caramelization process!
• Onion jam: if in a pin, then you can add some onion jam to the loaf. You won't get large chunks of sweet onion within the crumb, but it will still give it lots of flavor.

Storage tips

Once completely cooled down, you can slice the bread and enjoy it. Then, I like to keep the rest of the loaf flipped on its sliced part on the cutting board. The rest of the crust will keep the bread fresh for 48 hours or so.

For longer storage, you can transfer to an airtight bag or container, but know that the crust will soften in that case.

Freezing the bread is a great option if you don't enjoy it all within a few days. You can pre-slice it, transfer the slices to a freezer-friendly bag and freeze for up to 3-4 months, maybe longer. Thaw directly in a toaster or mini-toaster oven. It will taste just as good as when freshly out of the oven!

For more ideas on how you can store your loaf, check out this complete sourdough storage guide!

More sourdough bread recipes you might like

• Rustic sourdough bread
• No knead easy sourdough bread
• Whole wheat sourdough bread
• Sourdough sandwich rolls
• Sourdough buckwheat bread
• Sourdough quinoa bread
• Chocolate sourdough bread
• Same-day sourdough sandwich bread
• Oatmeal sourdough bread
• Turmeric sourdough bread

I hope you enjoyed this sourdough onion bread recipe! If you have any questions, please leave them in the comment section below. Your feedback is so helpful!

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