This is a short no fuss guide to help those who want to try a Natural Leaven without all of unnecessary fiddling about that has grown up about them. They are really simple to keep without daily feeds and discards. They can be forgotten and left in the fridge for a week at a time. I say this confidently as someone who has used them for more years than I am prepared to admit. This ‘fridge method’ is becomming the popular method now, as more people hear about it and try it.
A Natural Leaven is the same as a Sourdough Starter. Originally, they were just called leavens (In French Levain). Then yeast came along and home bakers forgot how to use them and somehow when they came back into use they were called Sourdough Starters. People now expect a sourdough bread to be sour. Supermarket bakeries have been known to add vinegar to breads with ordinary dough and then carefully affix a label saying Sourdough, before upping the price. Some now add lactic acid, now there’s progress. Give them their due, the big bakeries have spent millions trying to find a way of making sourdough with their machinery. Now they can, recently a commercial product, sterilised sourdough leaven, came on to the market. These bakeries can now add this sterilised powdered sourdough to their doughs without disturbing their yeast driven process. The dough is not been fermented using sourdough culture and it will not taste as good.
A good Natural Leaven is not sour, unless you want it to be. I read a Gourmand writing about them in 19th Century France bewailing the fact that it was becoming more common for bakeries to let their leavens become sour and so produced sour bread. I prefer the term Natural Leaven because mine is not sour, unless I make it so. This term is becoming more popular now. I am not keen on sour sourdough bread.
Old traditional bakeries of yore needed a leaven every day. So, at the end of the shift they would add flour and water to whatever leaven they had left and they’d leave it overnight in the warm bakery for the next morning. No discards and no fuss and it would always be sweet, not sour.
We home bakers don’t bake every day. If we leave our starter on a warm kitchen top it would become sour after the a couple of days. I will explain all of the why’s and wherefores in another article. Needless to say discarding a portion of it and feeding it every day is a lot of bother in an already busy world and it’s a lot of waste too unless you like sourdough biscuits.
We have fridges and popping the starter into the fridge takes all of the fuss out of it. No feeds and no discards.
There are two ways to go for someone just starting out. The first is the Natural Leven in the usual jar kept in the fridge and the second one is to use ‘Old Dough’, or Pâte fermentée in France.
Old dough is so easy I would say that everyone should try it, even if they don’t want to go down the whole natural leaven route. It is effectively the same as a natural leaven anf wit will confer the same increase flavours to the finished loaf.
Why use a natural leaven?
I have written about this in other articles. Simply put natural leavens have lactobacilli (usually abbreviated to LABs) in them as well as yeast. The the yeast and the LABs work together and even provide each other with their preferred types of sugars. They each prefer different sugars. They do not compete and actually ferment the dough together and keep all other fungi and bacteria out using complementary chemical defences. Together they make much more flavour than a yeast is capable of doing on its own.
Breads which are made with natural leaven have far more flavour, more even than a slow fermented yeast, or cold fermented dough, will ever have.
First of all, I would like to thank Charlie for putting me onto this method. It's something I've always ignored. Its so easy. I've linked his video at the end.
Next time you make a loaf add sufficient extra flour and water to make an extra 170g of dough. That’s about 6oz in the old tongue. When dividing the dough ready for shaping pull off that extra 170g / 6oz and pop it in the fridge in a container. 170g is sufficient to make a loaf using 500g, 1lb 2oz of flour. So, factor that up if you do bigger bakes.
Keep doing this every time you bake. Over time the commercial yeasts in the old dough will be replaced by natural ones and the Lactobacilli will move in after some four bakes or so, typically after some four weeks.
When you come to add your old dough to your next bake whisk it into the dough water before everything else. That will get it better distributed in the dough.
If you’re going away or are not going to bake for over a week pop it in the freezer. It is quite happy there and completely dormant. It will keep in a freezer for a year quite easily.
The common mistake with this method is to forget to pull off some dough for the next bake. A big paper note where it can’t be missed helps.
Easy Natural Leaven
How to get the Natural Leaven Started
To get it started from scratch take 50g wholemeal, or wholegrain flour, 50g of water, mix them and keep it in a warm place.
When you start to see bubbles, usually after 4-8 hours give it another feed of 50g wholemeal, whole grain, flour and 50g water, stir it in and leave it another period, usually overnight at this stage. I keep doing this until it is nice and bubbly. That is usually about two feeds after the initial mix. About 48 hours.
Don't worry if yours is slower to get going, sometimes they are slow. Don’t feed it if you can’t see bubbles. I've never had one fail ever, but sometimes they are slow to get going.
Wholemeal flour has more wild yeast on it than white flour and it is more nutritious for the yeasts, so they grow faster. White flour leavens take longer to get going.
If you want a white flour leaven it’s best to get it established with wholemeal flour and then take 50g of starter and mix it with 50g White Flour and 50g of water. This is referred to as feeding your starter across to a new flour. Rye flour, Emmer, Spelt and all of those work well in a leaven. Do not use Barley in a leaven. Barley has strong anti fungal properties and it is prone to slime moulds. Yes, that’s contradictory, but true.
It's a myth that getting some ancient starter is better. The wild yeasts and Lactobacilli will quickly displace anything that you bought. It takes about four weeks for the lactobacilli
A wholemeal starter can be used in any bread, but if you want a white flour starter, just take 50g of it and feed it with white flour and water.
Natural leavens can be stored in the freezer for months. The cold doesn't harm them.
Using your Natural Leaven
The illustration at the top of this article is of a natural leaven that is ripe and ready to use.
I have kept my sourdough starter in the fridge for many years now. No feeds, no discards. My natural leavens are 50:50 flour and water. e.g. 100% hydration. On a bake day I remove the starter from the fridge and feed it up to the weight I want, plus about 50g - 100g extra to have some to go back into the fridge.
It’s then left in a warm place for 4-6 hours when it’s ready to use. Whatever is left is mixed with 50g of water and 50g of flour and it goes straight back into the fridge. To be honest it sometimes goes into the fridge without a feed. I bake every three days. But, a feed before putting it back into the fridge will give you a week without having to think about it.
If I want to bake in the morning, I get it out of the fridge, feed it sufficient for what I need and 50g-100g left over and leave it in a warmish place overnight.
Don’t worry if you use it all in a bake. The scapings on the side of the jar will get it going again. Give it a 50g and 50g feed, scrape the jar sides down and leave it in a warm place to get it going a little (two to three hours) and then into the fridge it goes.
All of the starter is my preferment. I don’t do this thing of taking some starter to start a preferment. It’s not necessary. I flash the sides of the chilled jar under hot water from my tap to take the chill off it, so it comes up to 26 C quickly. This is then kept at 26C for 5-6 hours when it’s very lively and ready to be used.
If ever you don’t use it for too long and it gets acidic just take 50g of it mix it with 50g of flour and 50g of water and leave it on the side for a few hours. You might have to do this a couple of times to lower the acid level. Whatever isn’t used is thrown away. This is a very rare occurrence.
Please, do not screw the lid onto the starter tightly, or lock a Kilner Jar lid down with the rubber seal in place. The starter is producing CO2 and has the potential to burst the jar if sealed. A loose covering is enough. The Yeast and Lactobacilli are well armed to keep intruding bacteria out. They’ve been doing that for millennia and they’re good at it.
How much do I need?
The range of leaven used is usually 15% t0 35% by flour weight. Using more makes the dough ferment faster.
A good amount to guarantee success is to have 20% of the total flour weight coming from the leaven. So, if the recipe calls for 500g of flour 100g of that flour is in the leaven. As the natural leaven is 50% flour and 50% water to get that 100g of flour in the leaven you will need 200g of leaven. E.G. double the weight.
Warning: There are two conventions when noting the amount of leaven in a recipe. The old convention used by professional bakers is to quote the amount of leaven by it’s total weight including the water in it. This enables the baker to just tip the right amount into the mixer from a bucket. (Later edit - I see that some baking Colleges in the U.S are switching over to using flour weight as the conventional percentage measurement).
The best convention for home bakers is to quote the leaven only by the weight of flour in it. That way it’s much easier to make sure you’re using the correct amount of flour in the recipe. If you are following someone else’s recipe and they say x grams of leaven and they neither say whether that is the percentage for the whole leaven, or they do not give the hydration for the leave, then assume that is the weight of flour and that it is with 50% flour and 50% water.
Do not forget to reduce the weight of the water you add to your recipe by the weight of water in your leaven.
Converting a Yeast Recipe to a natural leaven one.
Simply exclude the yeast and take 20% of your flour off and use the same weight of water from the water you plan to add to the dough. That will put the 20% of flour back and do not forget to reduce your recipes water by the weight of water in your leaven. That will be half of its total weight. Job done.
Some might have noticed I have not taken a portion of starter to make a preferment for use in the bake. It’s simply not necessary, unless you want to use a Wholemeal starter to make a white leaven for a bake.
My starter has died? No, it probably hasn’t. As long as you haven’t heated it up it is still thriving. Scrape off any fungi on the surface (it’s mostly yeast) and start it off again with 50g from inside. Yeasts and Lactobacilli can go for months in a dormant state, just waiting for the right conditions.
To safeguard your starter, you can freeze some in an ice cube tray and keep it in the freezer for up to a year. I don’t bother. They are so easy to start from scratch.
Just to repeat, a leaven kept in the fridge only need feeding every five to seven days.
Please, do not waste your money buying a starter online. They work, but the yeast and lactobacilli will quickly be replaced by the yeasts in your flour and the bacilli from your environment. The classic one is buying a San Francisco Sourdough starter, I’ve done it. After a week or two I had a North London starter.