Sourdough Starter Maintenance and Troubleshooting

by Wojciech Sleczek August 28, 2021

If you're wondering how to get started with sourdough baking and learn about proper starter maintenance, you found the right place.

It may be overwhelming at first, especially if you've never tried before, therefore we have prepared a list of the most important aspects. Read through the points below. If your question remains unanswered, please leave a comment and we'll do our best to get back to you.

Remember that a healthy live sourdough culture is the core of your success, so it's important to provide it with the best possible environmental conditions. Things like temperature, hydration, and a proper jar with good ventilation all play a major role. We also recommend feeding starters with the best food available - this means quality organic flour with filtered water.

All of this, plus some basic manual skills, will make you a comfortable home baker, able to troubleshoot independently and proud of their sourdough baking outcomes. Read on!

FIRST STARTER FEEDING

Organise a clean container and note its weight while empty. Glass jars with wide mouth are best as they allow easy access to mix the contents and clean the walls (read more about recommended containers below). Put the container on a scale and zero the reading.

Using a spoon or a spatula, scrape off all starter from inside the plastic zip-lock bag you have received, and transfer to the jar. You can also cut one corner of the package and use it as piping bag to squeeze out all starter inside. You should be able to recover 40-60g of the starter, depending on how much was in the bag initially. Don't worry if you can't get it all out, as the culture will still work perfectly fine. Note the weight of the starter added.

Now add good quality organic flour and lukewarm water in 1:1:1 ratio by weight, and mix well until all flour is incorporated and there are no dry lumps. It is important to maintain consistent amounts of ingredients during feeding; if you received 50g of starter, add 50g of flour and 50g of water. Read more about recommended flour below.

Cover the jar with lid and set aside for 24 hours in room temperature. The exact time will depend on the age of the starter (i.e. how long has it been since the last feeding), the temperature of the environment and the water you used (warm = faster, cool = slower), and the flour itself (high/low protein content). Normally the first signs of fermentation are visible after a few hours. You will see bubbles forming throughout the container and the culture beginning to rise.

It's a good idea to put a rubber band around the container to mark the original level of the starter after feeding.

You will notice the starter continues to rise, forming bubbles and releasing gas (CO2), and has a domed surface, until it reaches its peak, when it will start to fall, or 'collapse'. Ideally, this is the moment to use it in your recipe to ferment the dough - provided you have sufficient amount, so about 20% relative to the amount of flour used to make that dough - otherwise, we recommend preparing a levain/leaven. Read a few points below about what a leaven is.

REVIVING DEHYDRATED STARTER

Put an empty jar on a scale and zero the reading.
Transfer 20g of the dehydrated starter inside.
Add 10-15g lukewarm water and stir well.
Put the container in a warm place for 1hr.
Add 20g of good quality flour and 20g of water; stir well.
Set aside in a warm place for 24hrs. You should have about 70-75g of a fresh starter available.
Don't worry if there are no signs of fermentation after 24hrs.
Discard half (about 30g) and feed with 30g flour and 30g water.
This extra feeding should make your starter fully active after another 24-48 hours!

During the process, you may stir the whole mix once or twice. This will help with aerating the culture and will ensure all starter granules are well incorporated.

Your starter will be active and ready once you see clear signs of fermentation - increase of volume, bubbles of CO2, change of texture. This may take up to 3 days to achieve, depending on the conditions. So keep the feeding routine until your starter builds up sufficient activity.

Use the starter directly in a recipe or prepare a leaven first. Read a few points below about what a leaven is.

CONSECUTIVE STARTER FEEDINGS

Your starter should be fed regularly at relatively consistent time intervals. The more often you feed it, the better. If you store it in room temperature, feed it at least once per week. By the time it reaches a full week since the last feeding, it may have gone somewhat dormant and it may take a bit longer to re-activate, however, we normally see activity back within hours. Our starters are fed every 12-36 hours, and therefore they are always active.

If you'd rather store your starter in the fridge, the routine will be different. Sourdough starters can survive much longer in cool temperatures. All processes slow down and the culture simply goes into a 'hibernation' mode. We have tested 2-4 weeks periods without feeding and had no issues with reviving. A few things to remember though:

Allow your starter to ferment the freshly added flour for about 24 hours before putting it to the fridge. The reason being in 2-8C which your fridge operates at, the yeast fermentation cannot proceed. The lactic acid bacteria (LAB) will still be active, though, until the whole culture hibernates.
Plan ahead - if you want to bake, take the starter out of the fridge, allow it to reach room temperature, and feed. Note it will take longer to reactivate, compared to one kept on the kitchen bench. So be patient and don't use it in a recipe until it reaches its previous activity. We recommend doing all this 24-48 hours before baking.

Upon each feeding session, it is recommended to discard half of the old starter, before replenishing with fresh flour and water. This is to remove some of the metabolic products of fermentation. That discard starter can be used in another recipe (like sourdough discard pancakes) or given away to a friend.

The process of consecutive feedings is very similar to the very first feeding: put the container on the scale and note the weight of the contents (remember to deduct the weight of an empty container). Discard half of the contents and replenish with fresh ingredients, maintaining 1:1:1 ratio of starter, flour, and water, by weight.

Mix well and set aside for 12-24 hours. After this time, you can:

use it directly to ferment the dough (as the 'pre-ferment')
prepare a leaven for even higher activity and to scale up the 'pre-ferment'
put it back on the bench and let it complete fermentation
or (if preferred) store in the fridge until the next feeding

Try to maintain minimum size of your mother starter, like 60g total weight. Low volumes are easier to maintain and there is less discard (or none at all if you plan it well). Consider feeding 20g starter with 20g flour and 20g water (at 1:1:1 ratio). You will only need about 40g for baking, if you prepare the leaven. The remaining 20g (60g minus 40g) can be fed again to yield 60g final weight. This way there is no discard and you only need minimum amounts of ingredients to maintain a healthy starter.

CONTAINER

Glass Mason or Weck preserving jars are perfect examples of containers suitable for maintaining your sourdough starter culture. These wide-mouth jars are preferred for easy stirring, cleaning, and access. They have 'breathable' lids with internal soft rubber rings that lock in freshness. A simple twist of the lid will release all excess carbon dioxide (CO2) and neutralise the pressure.

Upcycled jars will also be fine. Look for round jars as compared to angular/egdy ones (much easier to clean the walls). Clean thoroughly in hot soapy water and use vinegar to eliminate old odours (if applicable). You can also sterilise them with boiling water or in the oven, but this is not required.

Remember to note the weight of an empty jar. You need to maintain 1:1:1 ratio of all ingredients when feeding, so do a quick calculation how much starter is inside, and feed with flour and water accordingly.

Your starter will double its volume (and sometimes even triple) and release CO2, so make sure there is sufficient headspace. Keep the lid sealed but not too tight, so that the excess gas can escape under pressure.

FLOUR

Use the best quality flour you can get a hold of. Think about it this way: your starter is as good as the quality of the ingredients. So look for organic, sustainable, unbleached products, and filtered water (sourdough doesn't like chlorine).

Your starter will require the same type of 'food' it was made of:

Wheat starter should be fed with baker's flour (it's a high protein flour made by milling the whole wheat grain and sieving off the bran)
Rye starter should be fed with whole rye flour (note rye is a different grain that wheat, milled from the entire rye kernel with the bran saved; if you can't source whole rye, just use normal rye)

For routine baking, use the common baker's flour. It can he used as a base for your recipes, and mixed with heavier flour types, like wholewheat or rye. Keep experimenting with the ratios (best to start with 10-20% additions).

For pancakes, pizza dough, cakes, donuts, naan bread, brioche buns, etc. we recommend using soft wheat flour (type 00) to achieve that light, soft and airy dough.

In order to achieve more complex flavours of your sourdough, you can use special flours, like Einkorn, Khorasan, and Spelt as additions in the total dough mix. They are all special kinds of ancient wheat grains and can be found in good organic food stores.

STORAGE

One of the most common questions is: do I store my sourdough starter in the fridge or on the kitchen bench? And both answers are correct, provided you follow a recommended routine.

If you bake regularly, there is no need to keep the starter refrigerated. We never keep our starters in the fridge and they are always ready to use almost immediately. With regular feedings and ambient temperatures, they maintain high activity.

Note yeast are not able to perform fermentation in lower temperatures, and so they will not process the flour you have fed them with. It will take longer for your strater to reactivate and build strength. Fridge storage may be recommended for seldom bakers though:

If you're not baking, feed your starter every 2-3 weeks. Allow it to process its food for 24-48 hours, prior to putting it back to the fridge. The yeast will stop fermenting, but the lactic acid bacteria (LAB) will still be active for some time. Then the whole culture goes dormant (into hibernation). But it can't go forever though, so feed it regularly. Virtually any starter can be revived if needed, so don't panic if you waited too long in between feedings.
If you want to bake soon, you need to plan ahead. Get the jar our of the fridge, allow it to warm up, and feed with fresh flour and water. Note it will take longer to see the first signs of fermentation, even over 24 hours, so be patient. Then, it is best to prepare a leaven in a separate container (read below what a leaven is and how to prepare it). The mother starter may be put back back to the fridge, where it will eventually go dormant again until the next feeding.

Always keep the internal walls of the container clean as they may become contaminated. You will know once there's a foul smell. So after each feeding, wipe the walls clean with a damp paper towel.

Keep the container away from direct sunlight. Best to put it somewhere relatively warm (in a cupboard, near the stove, on top of your coffee machine, or simply on the kitchen bench).

LEAVEN / LEVAIN

A leaven, otherwise called a levain, is an 'off-shoot' of the mother starter, activated by feeding with generous amounts of flour and water (for example in 1:2:2 ratio), and allowing to ferment for a few hours until it reaches its peak, and then adding to the dough mix to commence bulk fermentation.

It lets you quickly scale up the amount of the 'pre-ferment' required in a recipe. Usually, it is 20% of the total amount of flour, so if the recipe calls for 700g of flour, then you need to add 140g of an active starter, or the leaven (0.2 x 700g = 140g).

We recommend maintaining only minimum amount of the mother starter (say, 60g in total), and so making the leaven ahead of time is strongly encouraged to achieve the best results.

The sourdough starter is in its most active growth phase when it is just about to 'collapse'. As it rises, it forms bubbles and its surface becomes domed, until it starts to fall. This is the ideal moment to use it in a recipe as the 'pre-ferment'.

But, you will not always have your starter in this phase the moment you want to bake. Therefore, we recommend preparing the leaven. Use a separate container (another jar or a small bowl). Keep it covered to limit drying. The idea is to use the whole leaven that's been prepared.

We normally use 20-25% leaven in our recipes, and use a feeding ratio of 1:2:2, for example:

40g starter + 80g baker's flour + 80g water

Regardless of the type of starter you use (wheat or rye), prepare your leaven using baker's flour. It takes a few hours for the leaven to reach its peak activity (the exact times will vary), and our recommendation is to prepare it just before going to bed, so that it's ready for a morning baking session.

FLAVOUR AND TEXTURE

To get the right texture, always ensure the flour is well incorporated and mixed with water, and there are no lumps of dry flour. Use a spoon or a spatula and stir. Push the mass down so that it's evenly distributed on the bottom of the container.

The wheat starter is a shaggy mass right after feeding, and becomes creamy like a custard after its fermentation is complete. It acidifies and becomes quite 'soupy' and very sour. Depending on the brand and the exact type of wheat flour used, you may want to use slightly less water than flour when feeding.

It may smell of paint, or a nail polish remover. It sounds crazy but these are signs of good health and indicate the starter is very ripe (and probably wants to be fed again).
You may expect a very tart, lingering, 'vinegary' flavour.
Creamy white, beige, yellowish colours are all normal.

The rye starter has a texture of airy peanut butter; it is somewhat dense but still spreadable. At flour to water ratio of 1 : 1 used when feeding, you should be able to achieve the perfect texture. It makes large bubbles as it rises, and will have different characteristics than the wheat starter.

It has a strong 'vinegary' flavour, too, but more on the 'fruity' and 'funky' side.
Brown, light brown, dark beige colours are all expected

Both types are capable of fermenting baker's flour (or in fact any grain type flour), so can be used interchangeably in your sourdough recipes.

TROUBLESHOOTING

"My starter is not active, it doesn't rise and there are no bubbles"

This is a very common issue and there may be a number of possible causes:

It doesn't get enough food
It is not fed regularly
The flour doesn't have enough protein
It is a wrong type of flour
It is too cold and fermentation cannot occur (or is very slow)
It simply needs more time

So make sure you feed your starter properly with fresh good quality flour, and (preferably) filtered water. Maintain 1 : 1 : 1 ratio of the ingredients. Use lukewarm water. Do not keep it too long in between feedings. Get a flour which is rich in protein (>11%) and make sure you use the correct type. Avoid cheap supermarket plain white flours. Look for baker's flour for the wheat starter, and whole rye flour for the rye starter. Keep the container in a warm place to allow yeast fermentation.

Give it a little bit more time in between feedings as the fermentation must eventually occur if the conditions are right!

"I left it for too long and now it smells bad... Have I killed my starter?"

It is very easy to revive an old sourdough starter, so if you are at this point, don't panic. If it has taken long to arrive in mail, this won't be an issue, too.

Depending how bad the starter looks (and smells), you may need to prepare a new clean container. Discard the mouldy or evidently bad parts, and reserve some clean-looking portion of the old starter. It doesn't need to be a large amount. Tranfer it to the new container (remember to note its weight).

Now feed with fresh flour and water at 1 to 1 ratio and put in a warm place. Give it 24-48 hours, and then feed again (refer to the recommended feeding routine above). Do this for 2-3 consecutive days and see if your starter is back to normal. Signs of fermentation should be visiblle within hours, and your starter should be rising in volume and releasing gas.

Note: microbes go dormant in unfavourable conditions (no food, lower temperatures), which is actually their survival mechanism. Once fed, and placed in a warm place, these conditions improve, so the starter can go back to life."

"There's a white layer on the surface, is it mould?"

This is rather unlikely unless it's really been a long time since the last feeding. Most probably, what you see on the surface is just dried out layer of flour. If it hasn't solidified, yet, you may just stir it back in. Over longer period of time, it may develop a foul smell, and then the top layer should be discarded.

That foul smell is caused by bad bacteria and they are nothing you want to have in your starter. The safest way would be to discard the top layer, and carefully transfer a spoonful of the 'good starter' underneath to a separate, clean container. Then you proceed with feeding which should revive the starter. Give it 2-3 more feeds and it will strengthen the good lactic acid bacteria and wild yeast.

The white layer may also be the strain of lactic acid bacteria - definitely not mould - and they are expected in your sourdough starter. It is perfectly fine to stir them back in.

Make sure you feed your starter regularly. Keep the container closed to limit drying. Do not use linen cloth or any similar materials in place of a lid, as it increases the risk of contamination. Always push the mass down and keep the walls clean. HYGIENE IS KEY!