Complete guide outlines how to make a sourdough starter and how to feed a sourdough starter, with day-by-day steps explained. We also explain how to freeze and dry soughdough starter and how to tell if the starter is spoiled.
How to feed sourdough starter: The flour
Basically you can use any flour for the production. Most often, rye sourdough or wheat sourdough is made. Rye in particular reliably brings the right microflora with it to start a new sourdough. You can support the work of naturally occurring bacteria and yeasts. For this, we recommend using organic flour with a flour type that is above 405. Type 1150 rye flour or whole grain flour are particularly suitable.
Sourdough cultures feed on flour. If there is no more food, these important cultures die and you can no longer use the dough. Therefore, you should take care of them and feed your sourdough regularly. In this way, the cultures remain active. We’ll show you step by step how to make and feed your sourdough starter.
How to make sourdough starter
Mix 50 g rye flour with 50 g water, leave to rest in a bowl with the lid loosely on for 12 hours. Then stir once and let stand for another 12 hours. This is the foundation of your sourdough starter. The next day you start the feeding process.
Wheat sourdough is basically made in the same way, just with wheat flour and with a little more flour than water. It can be dried or frozen in the same way as the rye sourdough starter. Sourdough can also be made from spelt flour. When preparing, you use 50 g each of flour and 40 g of water. Even later when feeding, it always gets a little more flour than water, otherwise it becomes very liquid. The wheat sourdough starter differs significantly from the rye sourdough starter in terms of its color.
How to feed sourdough starter
After a total of 24 hours, “feed” the rye sourdough with 50 g rye flour and 50 g water, stir well and let rise again for 24 hours.
After 24 hours, remove 50 g from the batch and feed it again with 50 g water and 50 g flour. Let stand again for 24 hours. Of course, you can also feed the whole amount here, but then the glass will soon no longer be enough. The leftovers can simply be added to bread dough and baked with … a kind of old dough or aromatic dough.
After a further 24 hours “feed” the sourdough with 50 g rye flour and 50 g water, stir well and let rise again for 24 hours.
After 24 hours, remove 50 g from the mixture again, feed with 50 g rye flour and 50 g water, stir well and let rise again for 24 hours.
After 24 hours, remove 50 g from the mixture again and feed with 50 g flour and 50 g water, stir well and let rise again for 24 hours. If your approach doesn’t have any bubbles yet, I would feed it with wholemeal rye flour and keep it warm. 28 degrees are ideal, I wouldn’t go above 32 degrees. This is possible, for example, on or next to the heater, in the oven with the light switched on (this does not work for everyone, always check how warm the oven is first), in a fermentation box or simply put in a towel and put on a hot water bottle.
Now the sourdough starter is ready. You can keep 50-100 g of it in a jar or screw-top jar in the refrigerator and use the rest for your first sourdough bread.
Now the first time, the entire amount can be taken off. If, for example, 100 g of rye flour, 100 g of water and 20 g of items are specified in the recipe, you will take 220 g off your starter. As soon as it is in the refrigerator, it is no longer sourdough, but rather a starter! The leftovers, 100-200 g are enough to put in the refrigerator, can simply be added to bread dough as an aromatic dough. If necessary, use a little less liquid and no more than 100 g with 500 g flour.
When sourdough starter is mentioned in recipes, it is always about the sourdough starter in the refrigerator. It only turns into sourdough bread dough if you mix it with the same amount of flour and water and let it rise for 20-24 hours.
Ongoing feeding and freshening up
As a rule, the sourdough starter should be fed once every 10-14 days. After feeding, the sourdough starter always stays at room temperature until it has doubled and then comes back into the refrigerator.
For feeding, take 50 g of the batch in the refrigerator and mix it with 50 g of water and 50 g of flour. Leave this until it has doubled, then put it back in the refrigerator. Sourdoughs have very different growth rates, so it can take 3-4 hours for one and 6-8 hours for the other.
If you need a larger amount of ingredients or sourdough, you can feed them with more water and flour. So you can easily turn 50 g of items into 500 g by feeding this batch with 225 g of water and flour.
Our sourdough starter lasted 3 weeks in the refrigerator without feeding. Whenever I go away for a long time, I feed it again the day before and add more flour than water so that it is quite firm. It may then be a little limp, liquid or a hard crust may have formed on the surface, or it may smell strange. As long as there is no mold, it is still good. It’s just hungry. Solid crusts can be removed, everything else can simply be mixed in with the next feeding. Then it may have to be fed for 2 days in a row and left outside so that it can get going again.
For sourdough bread mix, approx. 10-30% of the amount of flour is used, ie 100-300 g of the flour with the same amount of water and 10-30 g of the sourdough starter per kg of flour in the list of ingredients. For doughs with a long proof or refreshment loaves, sourdough starter can also be added directly from the jar to the bread dough without feeding it beforehand!
How to tell if the sourdough starter is spoiled
There are always a lot of uncertainties about spoiled sourdough starter … so I took a few photos of how sourdough starter can look after a few weeks without any food (see below… in all 3 cases it is still good!) Only the so-called Kahm yeasts have appeared on the surface. Kahm yeast is not a type of mold, but rather an aerobic yeast that forms when the sugar is used up and the PH of the ferment drops because of the lactic acid formation. It is a hunger yeast that indicates it needs to be fed. It is neither moldy ( then it would be furry on the surface), nor otherwise spoiled. If you remove this crust, it usually looks and smells completely normal underneath. If it were really spoiled, it wouldn’t rise up after the next feeding! However, if there is a furry mold on the top, this indicates it has spoiled and you should through it out and make a new starter.
Preserving sourdough starter
To be on the safe side, if it does go moldy or if you are gone for a long time and cannot feed it or if you accidentally process all of your sourdough without removing your sourdough starter for the refrigerator again, you can freeze it or make a backup by drying part of it (description below).
How to freeze sourdough starter
Place the jar with the sourdough starter in the freezer. Thaw to revive and feed once with 2 teaspoons of flour and a little water. Let stand for a few hours until the sourdough shows bubbles. Then put it back in the refrigerator.
How to dry sourdough starter
To do this, feed the sourdough starter with 200 g flour and 200 g water, leave to stand for 24 hours. Cover a baking sheet with baking paper and spread the sourdough thinly on it.
Let the sourdough starter air dry on the baking sheet for 2-3 days. Then break into small pieces and fill into a jar. Drying has the advantage that you always have a so-called “backup” of your sourdough. I make a new backup of the current sourdough every year, as it is getting better from year to year. It has already happened to me that I have prepared the sourdough starter for the bread dough and then processed it without taking any of it off for the refrigerator. Then I had to make a new sourdough, which took a long time to get this good. Now all I have to do is take a few flakes from my backup, stir them with water and let them stand. Then feed again with 50 g flour and water and my new sourdough is ready with an already very good quality.
How to make sourdough bread
In the beginning, the young sourdough starter does not have that much driving force, so more yeast should be used when baking bread. The older the sourdough starter gets, the better it gets and the higher the driving force. Some of the really good, well-established bakeries have sourdough that is decades old. The only important thing is constant feeding.
For a pure sourdough bread without additional leavening agents, it is necessary to have particularly active sourdough. To do this, you freshen up the sourdough starter 1-2 times, let it stand until it has doubled and use this active sourdough starter to make the sourdough.
If you want a properly acidified sourdough bread, let your sourdough rise at room temperature. If you want it milder, let it go warm at temperatures between 28 and 32 degrees. This will keep your pretzel and your finished sourdough much milder.