We’ve compiled the most frequent questions we are asked about what happens if your sourdough starter goes wrong.
What is a wild fruit water?
Wild yeast waters
I was first introduced to this by Polly, one of my students, in the early days of the School. She had travelled from Hong Kind for a course, and described a Chinese way of baking using wild yeasts from fermented fruit. She advised using cherries. The result was incredible, a delicate mild sweet perfumed yeasty bread. We use the wild cherries or grapes from my parent's vineyard, but there are many other fruits that make wild water including apricots, raisins, plums, and figs.
It is a very popular method in Asia. We call it Polly’s Wild Water. She explained that in Asia they don’t like the sourness of very long fermented bread, but they do love working with wild yeast to produce a lighter flavoured, fermented bread.
When you make a wild water as a starter, you are effectively capturing the Saccharomyces cerevisiae, the yeast naturally found in many sourdough starters and a species believed to have been originally isolated from the skin of grapes. You can literally see the yeast as a component of the thin white film on the skins of dark-coloured fruits such as plums. There are also naturally occurring lactic acid bacteria, but these are at low levels in comparison to a wheat sourdough, so this starter is not one I recommend when it comes to students wanting a more digestible sourdough.
Mature starters … but it smells of apples and it is so good
When the yeasts are aerobic, they are at their most active. Of course, when the yeast ferments in the absence of oxygen (anaerobic fermentation) it produces alcohol and slows down, which is why when you see a sourdough culture that has been left to ferment for a while without being aerated or refreshed it develops a thin layer of water and alcohol (called hooch) on the surface as explained above.
This alcohol provides a catalyst for additional flavour dimension to mature starters in the form of iso-alcohols which contribute to the esterification of organic acids with alcohols. In other words you get esters forming, which makes your starter smell lovely. It smells of fruit - ripe apples, pears and pineapple. The reality is though that when your sourdough is at this point, it is delicious smelling but way too acidic. It needs refreshing ASAP.
Mature starter smells of nail polish remover OR old cheese
Your starter is desperate to be refreshed if it smells of nail polish remover (acetone) or, even further down the line, old cheese (butyric acid). The sad truth is that the esters in your starter, whilst delicious, are in part due to the alcohol produced by yeast fermentation because it is too mature to use. The esters actually contribute little towards final bread flavour, and you will end up with an underproved and heavy loaf. Refresh your starter back to back at least three times before you bake.
Can I change the flour I use?
Yes, although continuity will build your microbes into a robust community. The same microbes getting fed the same flour will have the food they are most used to and hence a stronger ferment. However, I have often changed flour and over a couple of refreshments the starter takes to its new food.
What kind of flour should I use?
The kind of flour you use is up to you. I use British white, rye, spelt wholemeal, heritage grain, chocolate (using 20% cocoa powder) and beetroot (using pureed beetroot instead of water). I recommend three things though. Firstly that the flour you use is organic, secondly that it is freshly milled, and lastly that it is stoneground. This will give your microbes the best nutritional support and it adds extra microbes via the flour, which also supports the health of the ferment.
How long can you leave a starter for?
I’ve often joked that I actually run the RSPCS - Royal Society for Prevention of Cruelty to Sourdough starters. I have kept a starter for over 6 months and revived it. It goes very smelly. This is the butyric and hexonic acid. It smells like parmesan or old trainers, and gets a dark hooch on top.
Can you revive it? Yes. It has to be built up again in the same way you would start a new one.
Is it worth reviving? Well that depends how attached you are to it. If the starter has an emotional significance, then yes it is worth doing.
It will take a few days to get it going again with repeat refreshments, and sometimes it is simply easier to start again.
What if my starter has a layer of grey water on top of it?
This is called hooch. It is a protective layer. It’s like bouncers outside a nightclub door, keeping out the riff raff. It shows that your starter has been left for a while and needs refreshing. Just follow the same procedure as the holiday refreshment (above) to build it up again.
Help – I want to go on holiday. Does my starter need a babysitter?
Leaving your starter is tough one. I often leave my starter for up to 2 weeks without any ill affects. Some people like to leave it with a friend or neighbour. If that's not an option, you can maintain your starter by leaving the microbes in a super fit condition and reducing the acidity. Refresh your starter twice a day over 2 days before you go away, and in the final refreshment thicken it up to about 60g of water for every 100g of flour that you use. Reducing the amount of water slows down the enzymes, in turn this slows down the rate of acidification. When you get back, build your starter up again by giving it a good feed twice a day for 2 days. Then return to a normal refreshment schedule.
Should I start my own starter or get one from another baker?
For people who are completely new to sourdough, I suggest it is faster and simpler to get an established culture. This can be easier because the process of culturing the starter is done for you, and you get to bake bread straight away. An established starter is also likely to be more reliable in that it already contains active yeasts and bacteria, which have been populating the dough over a long period of time. An established dough is stable, active, and resilient. This means that in your first attempts at making sourdough bread you will be guaranteed a more pleasantly flavoured sourdough, which will encourage you to bake more. Most bakers, whether home or professional, are happy to share their starters.
My starter smells horrid
Your starter should not smell horrid at any time, or have black bits in it, or indeed any mould whatsoever. On a rare occasion you may have a good go at making your own starter only to find it smells or tastes horrid, or that the bread and other baked goods it produces aren’t all that pleasant. This means the bacteria that has occupied your starter is not the right kind and the lactic acid, which makes the starter inhospitable to other organisms, hasn’t got going. You will need to discard this starter and start over. This time move the location of your culture to a different room.
I most often find when I talk to people who are having difficulties with bad smelling starters, they are not refreshing often enough. You need to refresh daily when you are starting a new culture, and you must refresh regularly when maintaining it. Once a week is the ideal.
If you are just getting a starter going, do not use hot water because this can kill the microbes you are trying to culture . Use warm water at about 27 degrees C. And there is absolutely no need EVER to add any bakers yeast.
Sometimes using fruit can introduce live yeast and other bacteria especially on grapes, but to be honest the yeast you want to encourage is on the outside of the grains. It is naturally present in the grain that you use. For the best results, use stoneground organic wholemeal flour, because the milling process is at a much lower temperature so the yeasts will survive.
How and why do I convert a starter to white?
It is generally best to start a new culture with wholegrain or organic rye. These flours are full of naturally occurring enzymes and nutrients that encourage microbial populations to grow. It is however easy to convert your established starter to another flour, you simply refresh using the new flour. The advantage of using white roller milled flour is it takes longer to peak, because the microbes have to work harder for their food. You can use this to your advantage, especially when you are planning a bake to fit in with a schedule to suit you.
Will it float?
This is a myth. Yes white flour will float when it is ready. It will also float when it has past its optimal point. And both rye and wholegrain do not float in most cases – so you will be waiting a very long time if you are wanting a wholegrain or rye flour to float.
How do I make my own sourdough starter?
To create your own sourdough starter you just need two basic ingredients — organic stoneground flour and water, and some basic equipment and conditions.
It is important the your flour is stoneground as the roller milled process heats the flour up to temperatures that kill the naturally occurring wild yeast.
The conditions necessary to make a sourdough starter - a warm room. Not hot, not cold, just a room that is pleasant to be in.
A non-reactive container (sourdough starter is acidic and will react with certain metals) to make and store the starter. I prefer glass but plastic is fine too.
A whisk to incorporate air – you can use a whisk if you want.
A breathable cover or a lid such as a clean tea towel, coffee filter, or a loose fitting disposable shower cap.
You need to keep it in a space to catch your wild yeast with no other cultured foods nearby, or there will be a cross over and you might not get the yeast you need.
The easiest way to start is to put 150g of organic stonegound wholemeal flour and 150g of 34 C water in a large jar. Whisk the mixture vigorously to incorporate air because yeast likes oxygen to reproduce and cover with your breathable lid.
Allow your mixture to sit in a warm place for 12 to 24 hours. Between the 12 or 24 hour mark you might be lucky enough to see some bubbles, indicating that organisms are present, but if you don’t then don’t worry. Repeat the feeding by removing a cup full of the mixture, and replacing with 75g of flour and 75g of water, this time at 28 degrees. Stir vigorously, cover, and wait another 12 to 24 hours. From now on you will need to remove half of the starter before every feeding and discard it, so the starter you do have can multiply in organisms without your jar overflowing.
If you are somewhere warm and using fresh wholegrain flour you will see activity quickly - after about 3–4 days. But if you are in more temperate climates then it can take 10–14 days. The sourdough starter should be beautifully bubbly.
If it is ready to use then it will double in size, the time it takes to do this depends on the kind of flour, the amount of water and the temperature.
In our school generally, the ambient temperature is about 22C.
Rye flour doubles in about 3 hours.
Wholegrain doubles in about 4 hours.
White roller milled flour doubles in about 8 hours.
Once your starter does this, you have captured and bred enough yeasts and bacteria for your starter to be active enough to bake with.
What if my starter has mould on it?
Sometimes yeast flocculating on the top of your starter looks like mould. It is actually rather beautiful, and in this instance, you will need to trust your sense of smell. If it smells foul then discard it.
If you see black or red mould then you must also discard your starter.
Occasionally you can rescue a stater that has mould on it. You have to be very careful, get rid of all of the top of the starter. I recommend doing this outside as mould spores are a threat to your starter and can linger in the air for a few days waiting for somewhere to land.
If you find a creamy uncontaminated section at the bottom of the pot then you can double refresh with rye flour at 28C and see if it shows signs of life. If not, start again.