Starting and Maintaining a Sourdough Starter

This post shows how to start a sourdough starter from scratch. It also answers all questions on maintaining a sourdough starter.

A healthy and active starter is the heart of a good sourdough loaf. This post will show you how to set up a starter from scratch. It will also answer questions on maintaining a sourdough starter.

What is a sourdough starter?

It’s a pre-ferment made up of flour and water. A way to cultivate wild yeasts and healthy bacteria. Both the yeast and the bacteria are present in the flour and the air around us. This mix of yeasts and bacteria 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. This continues 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. Sometimes I’ll add in rye or wholemeal to speed things up. 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.

Starting a sourdough starter (at 100% hydration).

Before we get on to maintaining a sourdough starter, let’s make one first. 

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 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.

Keep your starter in a warm space such as a hot water cupboard, especially if it’s winter and your kitchen is cold. If you don’t have one you can set up your own little heated spot.

In a chiller bag add in a jar hot water sealed tight, along with your starter. Close the bag to keep the heat in. This works well to create a warm space though you’ll need to replace the hot water every 4-6 hours as it cools down.

Day 1: combine 50 grams flour and 50 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 50 grams flour and 50 grams water. This means, adding in a fresh 50g of flour and 50g of water and mixing it really well with yesterday’s mix. 

Day 3: Pour 50g of the starter into a fresh jar and feed it 50 grams flour and 50 grams water. (A ratio of 1:1:1.) Discard the rest.

Day 4:  Pour 50g of the starter into a fresh jar and feed it 50 grams flour and 50 grams water. Discard the rest.*

By day 4 your starter should be bubbling and have a slightly sour smell. It’s not ready to bake bread with but it should have enough acid to be used in discard recipes like pancakes and cookies.

Day 5-10: Pour 50g of the starter into a fresh jar and feed it 50 grams flour and 50 grams water. Discard the rest. 

By day 10 it might be ready to use. Test your starter’s activeness, as shown below. 

Starter Activeness Test

To test how active your starter is and if it’s ready to bake with, you’ll need your starter to double within 6-8 hours. You will also feed your starter at a higher ratio of flour and water to check if the yeast colony in your starter is large enough to inoculate this extra flour in under 8 hours. 

Take 1 part starter and feed it 2 parts flour and 2 parts water. Mix it well in a jar or glass.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. 

Pop the starter in a warm place, out of direct sunlight. In winter, use a hot water cupboard, a freezer bag with a jar of hot water in there or the oven with just the oven light on.

If it doesn’t double within 8 hours it will need a few days longer. Repeat the steps from day 3 and 4 with the starter and try the test again in a few days time.

Sourdough Starter F.A.Qs

My starter was frothy and bubbly on days 2 & 3 but now on days 4 & 5 it’s not rising.

Don’t fret! Chances are it was the lactobacillus bacteria in your starter forming those bubbles, and not the yeasts. Bacteria also create bubbles while they are converting sugars to lactic and acetic acid, but it’s the yeasts in the starter that will give rise to your bread. The yeast colony takes a little longer to establish themselves. Be patient and keep feeding and refreshing your starter

My starter has split and now has water forming on the top. 

This is a sign that your starter is hungry! Your starter might be fermenting a little too fast and the yeasts have run out of food. This can happen if room your starter is in is too hot.

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 weight of water and new flour. Measure out a separate amount in a new jar. For example, 60 grams starter + 120 g water + 120 g flour. 

I forgot to feed my starter for ages and now it’s dead.

Doubtful. It’s pretty hard to kill a starter! Unless it’s super contaminated with harmful bacteria or mould, chances are you’ll be able to resurrect it. Just start up again with regular feedings and discards.

My starter used to double in 6 hours and now it’s taking much longer.

Has the temperature changed? If it’s colder your starter will take longer to double. Move it to a warmer space such as a hot water cupboard. A zip-up freezer bag with a jar of hot water in it will create a nice snug space for a starter too. 

Will my starter grow mould or get bad bacteria in it?

If you keep up with regular discarding and feeding, in a fresh jar each time, your lactobacillus colony will thrive. As they do, the amount of lactic acid they produce will inhibit mould growth and harmful bacteria. 

A contaminated sourdough starter is pretty rare. If you do see mould growing on your starter or it develops a pink, red or orange tinge, discard it and start again.

It’s day 5, I want to bake with my starter and I’ve fed it 1:2:2 but it hasn’t doubled in 8 hours.

Your starter isn’t ready yet. It’s not colonised enough and there aren’t enough yeasts yet inoculate the newly added flour in under 8 hours. Keep on discarding and feeding for a few more days and then try again. 

Starters are so forgiving. Just look for the changes happening and adapt accordingly.  

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.

Now let’s talk about maintaining a sourdough starter. First, 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.

Maintaining a sourdough starter

Once you have made your bread dough, take the leftover starter and feed it again 1:2:2 before placing it in a sealed jar in the fridge. Starter will last in the fridge for weeks and giving it this extra feed before refrigerating it will give it some slow release food over this time.

Once you’re planning to bake again, here’s what to do next.

Take your starter from the refrigerator and feed, in a clean jar at the ratio of 1:2:2. Discard the rest.

Mix it together to create a thick paste and leave it to sit, covered with a tea towel. Again, you want it to at least double within 6-8 hours before you bake with it.  This freshly fed starter you’ve just built is known as a levain.

Once you have used what you need for your bread, feed the remaining starter 1:1:1 and place it back in the fridge for the next time you bake. You want to feed it before placing it in the fridge to keep that seed starter amount small and the acid content low. It makes for a much easier starter to work with.

Young starter vs Mature starter

The longer the time between the feeding of your starter, or the bigger your seed starter amount, the more acid that 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. A starter fed 1:1:1 has a higher amount of seed starter than one fed at 1:2:2 and will have more acid.

Using a starter with a low acid content allows your dough to be a lot more stretchable and easy to work with. A starter with a high acid content can make it very runny and tricky to manage. It can turn your dough into a wet mess.

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.

Happy baking!