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).
Day 1: combine 100 grams flour and 100 grams water in a glass container and stir very well. Leave in a warm place, covered with a cloth.
Day 2- Day 5: Feed your starter every day, 100 grams flour and 100 grams water. By day four your starter should be bubbling and have a slightly sour smell. By day five it should be ready to use. You can test if it is ready by dropping a blob in some warm water. If it floats, it’s ready.
Now it’s time to bake. Usually, a sourdough recipe won’t call for a huge amount of starter and you’ll have a lot of ‘discard’ starter left over. To maintain your starter for future loaves you won’t need all this old starter, in fact, you’ll tip most of it out, hence why it’s known as discard starter.*
*Luckily 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 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 a little of your old starter, some new flour, and some new water. An easy ratio to remember is 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.