Baking Sourdough Bread in a Toaster Oven – The Secret to Getting Great Oven Spring

Baking sourdough bread in a toaster oven wasn’t something I envisaged when we moved to an apartment without an oven. But baking sourdough in a toaster oven is better than not baking sourdough. Much to my surprise, my toaster oven sourdough bread turned out terrific. Here’s the secret.

Have you been put off baking sourdough bread because you only have a toaster oven? Well, so was I after we moved to a new apartment without a proper oven. But after a few months eating bad bread, I had to try baking sourdough bread in a toaster oven.

And I was in for a surprise. As I discovered, with a little extra attention to detail during shaping and proofing, it is possible to produce a great sourdough loaf from a modest toaster oven. The secret is getting great oven spring.

Before I tell you how to do that, we have a favour to ask. Grantourismo is reader-supported, which means we rely on income generated from our readers to continue to publish recipes and food stories. If you’ve made and enjoyed our recipes, please do consider supporting Grantourismo.

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Now let me share some secrets to baking sourdough bread in a toaster oven.

Baking Sourdough Bread in a Toaster Oven – The Secret is Getting Great Oven Spring

While bakers with domestic ovens that can reach 260°C have no trouble making sourdough boules, batards and baguettes, baking sourdough bread in a toaster oven that struggles to reach over 200°C is far more challenging. Why? Because it’s difficult to get great oven spring.

So what is oven spring and why is getting great oven spring important? Oven spring is the expansion of the bread dough during the initial baking phase. It’s generally considered that to get a good oven spring you need high heat – at least 250-260°C – to help the bread, well, spring.

Good oven spring occurs during the first 15-20 minutes of a bake, after which the baker reduces the heat down to around 220°C to harden and brown the crust. For my test sourdough loaves I’ve been baking batards (oval-shaped loaves) with a single score off-centre on the dough.

As the loaf expands, the score directs the steam to break through the surface of the loaf. This creates what is called an ‘ear’, the flap of dough that rises from the upper edge of the score. You can have good oven spring without a great ear, but you can’t get a good ear without great oven spring.

So, besides the ear, what do we look for in a sourdough loaf with great oven spring? Firstly, we want an evenly risen loaf. A final batard loaf should look like a rugby football sliced in half. The only part of the loaf that should have split is the score.

The ‘crumb’ (the interior structure of the loaf) should have evenly spaced holes. The size of the holes is determined by the hydration of the loaf, that is, the percentage of water (including the starter) to the percentage of flour. The higher the hydration, the more ‘airy’ the crumb should be.

People often talk about the blisters on the exterior of the loaf as an indicator of oven spring, but this actually comes from long (usually overnight) fermenting. Carbon dioxide (CO2) leaks from the surface of the dough during a slow ferment. A slow ferment also increases the sourness of the finished loaf. I always do an overnight ferment in the fridge for at least 12 hours.

So here are the secrets to getting great oven spring if you’re baking sourdough bread in a toaster oven…

The Secrets to Getting Great Oven Spring in Sourdough Bread in a Toaster Oven

Make Sure Your Sourdough Starter is Lively And At Its Peak

I’ve covered how to make your sourdough starter and maintain it in an earlier post. Once you have a good strong starter, there are several things you can do to time and test your starter for making dough that will result in good oven spring.

You need to note how long it takes your sourdough starter to peak after feeding and just how much your starter has risen when it’s at its peak. For instance, my recently revived starter that was resting in the fridge now takes 7 hours to peak and it peaks just shy of triple the initial amount and is quite actively bubbly.

When feeding the sourdough starter, I add 50g of both flour and water. To make the most of the peaking of the starter, I will use it at 6 hours, before it has fully peaked. I time this so that if I feed the starter at 9am, I’m mixing my bread at 3pm, finishing at around 6:30pm, ready for a bake the next morning at around 8am.

Using the sourdough starter just before it peaks is the key to all the processes of making the bread if you want a great oven spring.

Choose Your Flour and Flour Mixture Wisely

Strong white bread flour is what gives your bread great gluten development and structure, however, whole wheat flours or rye give add flavour. We currently use a blend of 80% strong white bread flour to 20% whole wheat flour.

If you’re experimenting by baking sourdough in a toaster oven for the first time, I would recommend going with 100% strong white bread flour (you can add a little extra salt for flavour) and work from there.

Folding Your Dough and Autolysis

Autolysis is a process in bread making where the flour and water for the bread are mixed together before introducing the starter and salt. This is usually left for up to an hour for small batches of bread.

I find, however, that this doesn’t make much of a difference to our dough – apart from the starter sometimes not mixing in with the dough very well. However, our mix is left for an hour before the first set of stretch and folds begin, which are then done half an hour apart.

Generally, I do three sets of stretch and folds, then check the structure and strength using the ‘windowpane effect’. This is where you take a small portion of your dough and stretch it in four directions until it’s a thin translucent membrane where you can see light through it. Sometimes it can take an extra set of stretch and folds, so don’t just leave it at three – trust the windowpane effect.

A quick note: I’ve found that a very gentle stretch and fold works the best. Do not pull the dough up until it breaks and don’t overwork the dough in the bowl. Just do a few stretch and folds each time.

Shaping and Proofing your Dough

Perhaps the trickiest part of the whole process of baking sourdough is shaping and proofing the dough. Shaping the dough without enough tension will result in a weak oven spring. Underproofing the dough leads to an uneven crumb, while an overproofed dough can result in a flat bread with no oven spring. Clearly it is better to underproof, as at least the bread will still be edible.

However, I have a formula that I use to get the best results. Once the dough has passed its ‘windowpane effect’ test, I like to leave it at 28°C for about 20 minutes before the pre-shape of the dough, and then another 20 minutes before the final shaping. After the final shaping the dough goes straight into a cold fridge for at least 12 hours and up to 36 hours for a really sour bread.

But back to the pre-shape first – and we have a recipe here with detailed photos – this is when you shape the dough into a taut ball, running your hands across the table and underneath the dough.

The art to it is knowing when you have reached peak tension before the ‘skin’ on the outside of the dough begins to tear. If it does tear, flip and flatten the dough out for 20 minutes before trying again.

One of the indicators that you are close to peak tension is that small (and sometimes large) bubbles form on the surface or ‘skin’ of the dough. You should pinch the big bubbles, but you can leave the smaller bubbles intact. Let the dough relax covered for 20 minutes before the final shaping.

This is when you must handle the dough lightly. Although you’re releasing some of the tension of the dough, the structure of the dough should remain intact. When you’re finally shaping a batard, you should see bubbles as you roll the dough up. If it’s very taut there’s no need to do anything more.

If you need extra tension you can ‘stitch’ the surface of the dough once it’s in its proofing basket with the seam facing up. Stitching is done by grabbing the dough alternatively from the left side and then the right side, and stretching the dough to get more tension in the surface of the dough (which should be facing downwards).

The Perfect Score

I always get a little paranoid when I see bakers doing intricate, decorative scoring of proofed sourdough loaves in a hot bakery. Why? Because I was always taught to get the sourdough loaves onto a tray after proofing and get them into the oven ASAP.

This is particularly pertinent if you have a toaster oven or any oven that is not the hottest. Putting the just-scored cold loaves into your toaster oven gives you the best chance of success.

This is why a simple, single score is one of the keys to baking a great toaster oven sourdough loaf. You do, however, need a razor blade of some description and it’s safest to use a bread ‘lame’. It needs to be a single angled cut away from the centre of the loaf. Of course, first we need to pre-heat the oven.

How to Bake Great Sourdough in a Toaster Oven

The first thing you need to do when it comes to baking great sourdough in a toaster oven is to test just how hot your toaster oven can get. You’re going to need an instant read oven monitoring thermometer (this is my pick for one).

You simply cannot trust the temperature dial and a little red light. For instance, with our toaster oven, I could set it on 250°C for a week and it will never reach 250°C. It maxes out at 220°C. Do this once to check the maximum achievable temperature and there’s no need to waste electricity in vain waiting for the temperature dial to move.

I use a Dutch oven that will just fit in our toaster oven. If you’re using a Dutch oven, it’s important that you place it in the toaster oven when it’s cool and then turn the temperature to maximum.

To prepare the sourdough loaf for the Dutch oven, I like to have two sheets of oven paper placed on a pizza peel and tilt both the banneton and the pizza peel to transfer the loaf to the peel. Score the bread and have a water spray bottle ready.

Remove the Dutch oven from the toaster oven and quickly shut the door to the oven. Place the Dutch oven on a bread board.

Take the lid off the Dutch oven and, lifting the loaf up by the oven paper, place it in the Dutch oven. Spray water liberally over the loaf and under the parchment paper. Put the lid on the Dutch oven and put it back into the toaster oven. Set a timer for 20 minutes.

Note that most toaster ovens have a mechanical timer that will turn the oven power off when it ‘chimes’ zero time left. Turn the timer to full before baking so that the power does not go off during a bake.

After 20 minutes open the toaster oven and remove the Dutch oven lid. At this point the bread should have risen to its maximum amount of oven spring. If your toaster oven miraculously can go above 220°C, turn it down to this temperature for the rest of the bake.

The second half of the bake hardens the crust and colours the bread. For a light-coloured loaf, usually 20 minutes is enough. If the ear of the bread has really risen (congratulations!) you might want to place some aluminium foil over the ear to stop it from burning.

Toaster Oven Buying advice

I’ve used so many of these toaster ovens over the years of staying in holiday rentals where cooking appliances consist of a couple of hotplates and a toaster oven. Most are barely adequate. The main problem with toaster ovens, besides weak heat retention, is that they are not really made to work flat out at the highest temperature. Seals tend to go hard and knobs eventually fall off about the same time the handle packs it in.

I can’t really recommend many of the toaster ovens I’ve used, however, in the better-equipped apartment rentals that we’ve stayed in over he years, a couple of toaster ovens have really stood out.

The first toaster oven I recommend is the Breville BOV800XL Smart Oven which has a lot of functionality aimed at the microwave crowd with settings like ‘cookies’, ‘bagel’ and ‘pizza’, but it works amazingly fast due to the quartz elements for heating. The best bit, for a toaster oven, is that it can hold 230°C all day.

The second toaster oven recommendation is the smaller Cuisinart TOB-260N1 Chef’s Convection Toaster Oven. It has similar functions and features of the Breville toaster oven, but doesn’t have the fast heating abilities of it. However, once up to temperature, it can hold 230°C, quite enough to bake sourdough bread with and to achieve a great oven spring.

Please do let us know if you end up baking sourdough bread in a toaster oven and you follow my advice, or if you’ve been baking sourdough in a toaster oven for a while and have had success, then we’d love to hear from you.