A healthy and active starter is the heart of a good sourdough loaf.
What is a sourdough starter?
It’s a pre-ferment made up of flour and water and a way to cultivate the wild yeasts and healthy bacteria that are present in both the flour and the air around us. It is this mix of yeasts and bacteria that provide not only the rise in the bread but also sourdough’s signature tang.
Making a sourdough starter is relatively simple. Water and flour are combined and regularly added to for a number of days until it has formed an active, bubbly collection of wild yeasts and friendly bacteria (lactobacilli.)
You can use a gluten flour of your choice, I usually stick to plain unbleached flour for my starter though sometimes I’ll add in rye or wholemeal to speed things up as those sorts of flour seem to contain more yeasts and make things ferment a bit faster. I have not yet tried this with any gluten-free flours.
Once your starter is active, it is ready to be baked with. However, it doesn’t end there. After you have made your loaf, you don’t want to be having to start a fresh starter every single time you want to bake. Instead, you want to maintain your existing starter, feed it and keep it alive for the next time you bake.
To maintain your starter you take a little bit of the old starter and add some fresh flour and water. How much you take and how much you add differs for each baker but I’ll run through how much I take and why. First though, let’s make the starter.
I make a sourdough starter at 100% hydration. All this means is that I always add the same weight of flour as water when I feed my starter.
Starting a sourdough starter (at 100% hydration).
Starting a starter can be different for everyone. It depends on the temperature of the room, humidity, yeasts in the air and flour. This can all change how quickly or slowly your starter grows and becomes active. Here is a basic guide on getting started
Day 1: combine 100 grams flour and 100 grams water in a glass container and stir very well. Leave in a warm place, out of direct sunlight, covered with a cloth.
Day 2- Feed your starter 100 grams flour and 100 grams water. This means, adding in a fresh 100g of flour and 100g of water and mixing it really well with yesterday’s mix.
Day 3: Pour 100g of the starter into a fresh jar and feed it 100 grams flour and 100 grams water. (A ratio of 1:1:1.) Discard the rest.
Day 4: Pour 100g of the starter into a fresh jar and feed it 100 grams flour and 100 grams water. Discard the rest.
By day 3 and 4, your starter should be bubbling and have a slightly sour smell.
By day 5 it might be ready to use, though more likely it will take up to 10 days for a starter to be fully active.
To test how active your starter is, you will feed a little bit of the starter, this time at a 1:2:2 ratio before baking (see ‘Bread making day’ instructions below.) If it doesn’t double within 8 hours it will need a few days longer. Repeat the steps from day 3 and 4 the leftover starter.
*Things to watch for:
If your starter starts to split and you see water forming on top, it’s a sign that the yeasts have run out of food! This might be because it is too hot and your yeasts are multiplying too fast for their food source. If this keeps happening you can start feeding your starter at a ratio of 1:2:2. This means measuring how much starter you have and adding double the amount of water and new flour. Measure out a separate amount in a new jar (say 60 grams starter) and add in 120 g water and 120 g flour.
Starters are forgiving at this point! Just look for the changes happening and adapt accordingly. A hungry starter is the number one reason that they don’t work!
Bread making day
6-8 hours before I start my dough, I take 65g of my starter and feed it at a ratio of 1:2:2. This means 1 part starter, 2 parts water and 2 parts flour. I add this all to a new, clean jar. In 6-8 hours this should double. Doing it this way allows you to control the acid content in your starter AND it will be a clear indication that your starter is active and ready.
This 65 + 130 + 130 makes 325g of new starter. Of this 325g I would only use 150g or so for a loaf of bread. The leftover starter is what you can then use to refeed and create the next starter.
What about your original starter (that you took the 65g from?)
There are plenty of sourdough discard starter recipes such as my Sourdough Starter Chocolate Cake or crumpets, pancakes, crackers…
Maintaining your starter
First up, if you’ve baked a loaf of bread and you don’t plan to bake again straight away, just pop your leftover starter in the fridge. The whole thing, in a sealed jar. It can actually last for a couple of weeks in the fridge without having to do anything. But if you’re planning to bake again, here’s what’s next.
Take some of this starter, some new flour, and some new water, at the ratio of 1:2:2.
One part starter, two parts flour, and two parts water.
I usually take about 65g of existing starter and add it to a new glass jar along with 130g flour and 130g water.
Mix it together to create a thick paste and leave it to sit, covered with a tea towel. You want it to at least double before you bake with it. If you tie a rubber band around your glass jar to mark where the starter came up to before it rose, you’ll be able to see how much it has risen later on. (Thanks for that brilliant tip Dayna).
I either feed my starter the night before and leave it overnight to use in the morning or I feed it in the morning and bake in the afternoon. It usually rises quicker in the day as it’s warmer so doesn’t need to be left as long.
Young starter vs Mature starter
The longer the time between the feeding of your starter, the more acid accumulates in your starter. A starter fed and used within 6 hours will have less acid than if it was fed and used 12 hours later.
Using a young starter allows your dough to be a lot more stretchable and easy to work with. A more mature starter with a higher acid content will bring a much more sour flavour to your dough and is better if you are using flours with a lower protein content as it contains more acid which helps tighten the gluten strands. I learn a lot about starters and sourdough in general from Trevor Jay Wilson and I suggest you have a look at his stuff too, especially his elusive open crumb!
The world of sourdough is an exciting place and everyone has such a different take on their bread and a different recipe. One thing I’m sure everyone will agree on is a healthy active starter is a key ingredient.