Sourdough

I’ve found myself doing a more than average amount of baking over the last year or so, including bread and in particular sourdough. Here are some notes on the process that I follow to make sourdough.

Sourdough starter

As you may know, sourdough is a type of bread made using ‘wild’ yeast. Before making your sourdough bread, you’ll need a sourdough starter. As part of the bread-making process, you grow the starter with flour, increasing its volume, and you should be able to save some for next time and in theory never run out.

I’ve put a few notes on the starter below (and see the link in the ‘Extra shots’ section), but sourdough starters are probably at least one topic all of their own and for this post I’m going to focus on recording the steps I follow to create a loaf.

The levain

The first stage is to grow the starter to form a fermenting flour/water mixture known as a ‘levain’. The montage below shows how this looks.

1. About 50 to 100 g of starter saved from last time
2. Add 150 g flour and 150 g water and stir
3. Cover and leave to rise for a few hours (at least 3-4 hours depending on temperature)
4. The levain has started to bubble. It would probably be ok to use at this stage
5. I left it a further few hours, by which time it was foaming as seen in the last picture

Mixing the dough

Transfer 300 g of the levain to the mixing bowl, add 450 g flour, a teaspoon of salt and about 225-250 ml water. Set the remaining levain aside to keep as the starter for next time.

Mix the dough for 5 minutes on a low speed. After mixing it will still look fairly wet. It thens needs to ferment for several hours (I aim for about 4) before shaping into the basket. Preferably during this time fold every hour or so (in this case I only managed once). These foldings don’t seem too critical in my experience but generally seem recommended. I tip the dough onto a floured surface (you can shuffle more flour under it using the scraper if it tries to stick) and then stretch each side outwards and it fold over aiming to end up with a somewhat square piece of dough.

Shaping

Once the fermentation is done, I give the dough a final shaping and leave it to prove. I’ve mostly been proving my loaves in a round basket (as in the pics below). There are slightly different techniques for other shaped baskets and the basket isn’t essential (you can prove it on a cloth, maybe with a slightly drier dough in that case to avoid excessive flowing).

If using a basket, it’s best to flour that basket ready before you start folding. The basket can be generously floured to stop the dough sticking during the proving. Sprinkle flour into the basket from a slight height to spread evenly. It can help to hold the basket at an angle so that the part the flour is currently landing on is more horizontal.

For shaping into the round basket, the dough is first folded. Working round the dough, stretch out a piece of dough, fold it over to the far side, move round a bit and repeat until you’ve gone right round. I aim for 5 such folds.

Then flip the dough and use your scraper and other hand to tidy the shape into a ball/boule. Use your scraper and hand to rotate the dough, pushing dough under the boule as you go and stretching the top surface. Finally, flip the dough again into the basket (so the side that was facing the work surface is now upwards in the basket)

The following pictures illustrate this part of the process:

1. The basket before flouring
2. The basket after flouring
3. The dough after the first two folds
4. The dough after all five folds
5. The dough flipped and shaped into a boule
6. The dough flipped again and placed in the basket

Proving

Next, the dough needs to prove in the basket. You can either do this for about 4 hours at room temperature or arrange to get to this point at the end of the day and put the dough in the fridge to prove more slowly overnight. The overnight method has the advantage that the loaf is ready for baking first thing next morning so the bread is fresh the next lunchtime!

Here’s the loaf after proving overnight in the fridge:

Baking

Preheat the oven, then turn the loaf out onto a well floured baking tray. If the loaf has any trouble dropping from the inverted basket, don’t be afraid to use your fingers to loosen it.

I should note that the use of the baking tray and a slightly moderate initial oven temperature (225°C) rather than a pizza stone and a fiercer temperature is a bit controversial. Supposedly it might result in a crust that is very slightly less crunchy, but doesn’t seem to make a big difference to me. I started with the baking tray approach after my pizza stone broke clean in two mid-bake - before that I was using a temperature around 250°C. I’ve also not bothered with adding steam from a baking dish of boiling water. In my experience it didn’t seem to make much difference to the end result and I’m not convinced it’s great for the electric oven. Right before putting it in the oven I score it with a grignette.

Baking is for an initial 15 minutes at 225°C followed by 30 minutes at 180°C. Then remove from the oven and place on a cooling rack. During the early part of the bake, it’s likely to initially flow a little (don’t panic) before springing to it’s eventual shape.

The following pictures show:

1. The grignette (aka lame) used for slashing the loaf
2. The loaf turned out onto the floured baking tray before and after slashing
3. The loaf flowing a little and then springing back in the oven

After cooling, it’s ready to eat. Here are some pictures showing it cooling on the rack and then cut to show the crumb:

Eating

Here are some sourdough egg and mayonnaise sandwiches made from the loaf:

Recipe notes

Starter

To create a starter in the first place will take a few days during which you repeatedly ferment and replenish a flour/water mixture (approx 100% hydrated). As I understand it, there’s generally enough yeast present in the flour and/or your kitchen without having to go out of your way to add any. Once you have a starter going it can be kept dormant in your fridge potentially for months if required (i.e. if you don’t want to make sourdough for a little while)

Not got too much detail to add on this part as it’s been months since we revived the starter that had been lurking at the back of our fridge for years. Or perhaps that one really was dead and we just started a new one, who knows…

If I remember, correctly to create our original starter (back in the mists of time), we followed steps from a book that included adding the skin of an organic grape and potentially parading the starter in the yeasty air of the garden and doing a small dance. Pretty sure neither of those parts were necessary.

If your starter is working well the smell should be reminiscent of yoghurt. It seems that the starter contains a symbiotic mixture of yeasts and bacteria similar to those used for yoghurt.

Flour

With flour being the main ingredient it does seem plausible that choice of flour can make a big difference to the outcome. Ideally it generally seems recommended to use a strong (i.e. high gluten/protein) white bread flour for sourdough. I haven’t experimented with a lot of different flours, but did see noticeable differences between a generic ‘bread flour’ (sold by the sack from the bakery of a local supermarket at the start of lockdown) and a high gluten flour marketed as ‘ideal for sourdoughs’ (Marriage’s ‘Chelmer White’ ). The regular flour was able to make a perfectly serviceable sourdough loaf, but was able to hold a little less water in the dough before becoming sloppy and the loaves produced had a slightly less open texture.

Hydration

Another key factor is the amount of water incorporated into the dough. Generally this hydration is expressed by bakers as a percentage of water to the weight of the flour. For the recipe above, there is a total of around 400 g of water (150 g from the levain + 250 g added before mixing) and 600 g flour (150 g from the levain + 450 g flour) giving a hydration of 66%. That seems to be towards the lower end of hydrations recommended for sourdough.

I did experiment with higher hydrations, but found that they were harder to work, and more prone to flowing in the oven, without giving any better result. With a more hydrated dough (e.g. around 70%) it seems to be more important to fold the dough a few times during proving, but I’m doubting whether the improvement that gives comes from anything other than the flour that is incorporated during these folds.

The recipe I’m using here is similar to Marriage’s White Sourdough Loaf formula.

Reducing the water added at mixing to 225 g gives a hydration of 62.5% which is a little dryer still, but again easier to work with (ideal if you don’t expect to have time for much folding). This reduction in hydration didn’t have a big impact on the texture of the bread, but maybe makes it slightly more prone to bursting out into ear(s) away from the locations you’ve slashed.

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Extra shots

• Discussion and study of sourdough starter bacteria and yeasts https://asm.org/Articles/2020/June/The-Sourdough-Microbiome
• Bake with Jack has a blog on bread and sourdough and also a baking equipment shop https://www.bakewithjack.co.uk/