Our trusty, fruity rye sourdough starter culture
A lot has been written about sourdough starter cultures. You can find long and elaborate articles on how to make your own starter while using things like pineapple and grapes. They are almost mythical creatures to be treated with the utmost care and fed every evening at the same time while standing on your head. The truth is much simpler. My rye starter seems almost indestructible. And the only thing I did is mix some whole grain rye flour with water and wait…
What is a starter?
A starter is a piece of dough which contains wild yeast and bacteria which you use to make your bread. The wild yeast produce carbon dioxide (and a bit of alcohol too) to make your bread airy. It is the bacteria that can give your bread the sour taste, this is because the bacteria transform the starch of the flour into lactic acid, acetic acid and alcohol. Both the acid and the alcohol give sourdough bread their unique and interesting taste. You add an amount of your starter to a larger amount of flour and water mixture like you normally use commercial yeast to a poolish or a biga preferment. It works just the same only slower. Commercial yeasts are selected and bred for speed by the big yeast companies but wild yeast works at a slower pace. This is why bread recipes for sourdough bread tend to take much longer and consist of more steps.
Why a rye starter culture?
For my sourdough baking I use a culture which is made with 100% whole rye flour. A sourdough culture based on rye flour is easier to maintain, it does not go into a slurry like a wheat flour starter when you forget about it, it is easier to stir because it has almost no gluten and it smells very very nice, a bit like fruit. It is also very forgiving in the amount you feed it. You feed your culture after baking to replenish your stock. Normally I only feed it once a week, after my weekend baking, I just give it a few table spoons of water and rye flour, stir and ready!
The birth of a new starter culture
Before starting your own culture
First thing: work clean! Use a clean jar and always use clean spoons to stir and add flour to the mixture. The organisms living on your hands can contaminate your starter and spoil it! Throw away your starter and start over when it develops an awful smell or grows moldy in whichever color, it probably has picked up a bad bacteria in the first feeble stages of the starters life.
After some research I found that the most likely truth of the source of the yeast and bacteria is the flour itself. The yeast and bacteria live on the outside of the grain (just like the yeast to make wine lives on the skin of the grapes). This is why you need (preferably organic) whole grain rye flour, because you need the outside bran of the grain as a source of yeast and bacteria.
I start with a relative wet starter and when the starter is alive add more flour to maintain a more stiff starter. I start with a small amount of water and flour as not to waste too much flour, because you have to throw halve of the starter away with each refresh. When your starter is alive and kicking you always can scale up the size of your starter simply by adding more water and rye flour.
Be sure to use water which does not contain chlorine. Water companies sometimes add a little chlorine to your tap water to kill all bacteria and probably also the yeast in the water, so it is not a good idea to use this for building a sourdough starter. If in doubt you can use bottled water.
And now on with the easy steps!
Day 1: Take a small clean jar (I use a 400ml jam jar) and add 40ml of water and 40g of whole grain rye flour, stir with a clean spoon for 30 seconds. Draw a line to mark the height of the mixture with a permanent marker on the jar so you can see any activity easily. Loosely close the lit of the jar and store at room temperature (about 20-21 degrees Celcius) out of direct sunlight for 24 hours.
Day 2: If you are lucky you should see some little bubbles of air in the mixture. The smell of the mixture at this stage is not very nice, a bit musty but not totally off putting. Add 20ml of water and 20g of whole grain rye flour. Stir with a clean spoon for 30 seconds. Draw a new mark line if needed. Loosely close the lit of the jar and store at room temperature out of direct sunlight for 24 hours.
Some bubbles are visible after 24 hours – It’s alive, its alive…
Day 3: Your mixture should now be getting active. Mine did more than double in size during the last 24 hours. If your mixture is not very active yet, throw away half of the mixture and repeat the directions of day 2 again. The smell of your mixture should be a little nicer at this stage. When your mixture is active, throw away two third of the mixture and add 30ml of water and 30g of whole grain rye flour, stir with a clean spoon for 30 seconds and store at room temperature.
This is called refreshing or feeding your starter. By throwing out half of your mixture and adding new rye flour you give the starter fresh food (the rye flour) to work on, so all your new yeast and bacteria can get ‘stronger’ and multiple again. You also dilute the alcohol and the acid they produce so the yeast and bacteria do not ‘poison’ themselves.
Day 4: Your starter should now be fully active and strong enough to double or triple in size during a 24 hours time period. We need to refresh it again before we can use this starter because the acid producing bacteria need more time to develop than the yeast. So throw away two third of the mixture and add 30ml of water and 30g of whole grain rye flour, stir with a clean spoon for 30 seconds and store at room temperature.
The starter is now 36 hours old and has tripled over the past 12 hours after feeding
Day 5: Your starter should at least double in size consistently after each refreshment to be ready for your first baking project. If your culture does not double in size consistently after day 4 or 5 repeat the directions of day 4 until it does.
At this stage your starter should be developing a nice fruity smell during the next few days. You can now let your starter rest for a few days. I keep my starter after refreshing on the counter for 12 to 24 hours for it to double in size and develop and then store it in the fridge. Mine developed a nice fruity tone on day 6 which got even nicer on day 7. Just keep using and maintaining the starter from now on, after a while the color of your starter should get a little bit more beige after it has tripled after a feeding (notice the difference in color of my old and new starter). This is a sign of maturation of the starter and the production of acid.
How to maintain your starter
A rye starter does not need much maintenance. We store our starter in the fridge. We bake (almost) every weekend so our starter is being refreshed at least each week. We keep about 120g of starter of which we use about 60g up to 100g each week. So after taking out the amount for baking, we just add water and rye flour and stir, so we have about 120g of starter again. We keep our starter quite stiff, almost like a thick paste. The reason for this is that it will develop a lot slower with less water, so it matures during the week and is ready for baking the next weekend.
After feeding we keep the starter on the kitchen table at room temperature (usually around 21C) for about 12 hours so it can develop and double or triple in size. When it has developed, we store it in the refrigerator until the next baking session. Always wait for your starter to at least double in size before storing it in the fridge, a starter should be fully developed before it can survive in the cold. A starter kept in the fridge should at least be refresh every two weeks. A starter kept on your counter should be refreshed at least every three days.
If we want to bake, we take it out of our fridge and use it directly for a poolish or biga. Then refresh it, so it will be ready and active for our next baking session. That’s it!
Small video clip timelaps of rise of rye sourdough starter
We can also give you a head start with our own active WKB rye sourdough culture. You can find it in our Bakery Tools webshop (only shipped within the Netherlands, Belgium and Germany!). But don’t be afraid to give it a try yourself first!