Everybody likes their sourdough a certain way, I like my sourdough bread to be as sour as possible. So I started experimenting, I tried all possible types of flour, I tried different types of starters, experimented with different fermentation periods, and more, until I found out how to make my sourdough as sour as possible.
After all those different experiments I came up with 21 different things that you can do to make your bread more sour. So I decided to write this article for people who just like me enjoy a truly sour sourdough bread.
Here are 21 different ways in which you can make your sourdough bread more sour.
1. Long Fermentation Time Increases Sourness
The sourness of the sourdough bread mostly comes from the good bacteria that live in it, which produce acetic acid when they eat the sugar and starches found in the flour.
So, the longer you let your dough rise (ferment), the more time the bacteria will have to eat up the sugar which makes the bread taste sweet, and the more acetic acid they will produce, which tastes sour.
On average sourdough bread should be left to ferment for at least 6 hours, but you can let it ferment for up to 3 days. So don’t be afraid to let your dough ferment for longer if you want to increase the sourness of your bread.
Through the article, you will see me mentioning the bacteria that live in the sourdough, if you don’t know about them, you should know that this is completely normal for sourdough to have them, they are good bacteria that don’t even make it into the bread itself, and they are also called probiotics. If you want to know more about them, you can check out my article: Does Sourdough Contain Probiotics? (+ What They Do)
2. Don’t Feed The Starter Too Much
While it’s usually recommended to feed your starter as often and as much as it needs, if you want a more intense sour taste, you should actually feed it as little as possible.
When the starter doesn’t get fresh flour and water for a long period of time it will start to develop more acetic acid, which is responsible for the taste.
If you want to make your sourdough sourer using this method, you should feed your starter once every two days, instead of once per day. This will help you get the taste that you want and it will keep the starter healthy and active.
3. Use the Liquid on the Top (The Hooch)
This one is closely related to the last tip.
When you don’t feed your starter daily, it will start developing a liquid on top, alongside the acetic acid.
This liquid is usually referred to as hooch, and is usually thrown away, as it has no use for most people. But if you are looking for a really sour taste, you want to keep it and use it when making the bread.
What I like to do with the hooch is to drain it in a glass, and when feeding the starter, instead of water using the hooch. I usually don’t have enough hooch to substitute the whole quantity of water, so I use normal water for the rest. Doing this will definitely improve the sourness of your sourdough bread.
4. Don’t Enrich the Sourdough Bread
Enriched sourdough tastes amazing, adding just a little butter or some olive oil can give the bread a great texture and a unique flavor. But if you want a truly sour sourdough bread you should avoid enrichments.
All enrichments, whether they are butter, milk, yogurt, or oil, will make sourdough bread taste sweater.
Traditionally sourdough is made using only flour, water, salt, and starter, which is also a combination of water and flour. Those basic ingredients are what made sourdough bread be known as a sour bread, hence the name.
5. Use Whole Grain Flour for a More Sour Taste
The main difference between whole grain flour and plain white all-purpose flour is that the white flour doesn’t use the whole grain, it only uses one part of it, while the whole grain, as the name implies, uses all of it.
As a result, the whole grain has more nutrients, which allows the bacteria in sourdough to produce more acetic acid, which gives sourdough its specific taste.
Changing the flour that you use will result in clear and immediate results.
6. Rye Flour Makes Sourdough Bread Even More Sour
Out of all flour types, rye flour is the best choice if you want to make a really sour sourdough bread.
Due to its unique enzymes, complex carbohydrates, and sugars, rye flour is like a superfood for sourdough, which makes the bacteria extremely active, so they produce more acetic acid, which is responsible for the sour taste of the bread.
There are two very important things that you have to know before making bread with rye flour.
The first one is that it’s not advised to make a 100% rye flour bread, sourdough, or otherwise. Rye flour on its own can make the texture of the bread really gluey, which is far from what you want in a bread. So it’s suggested not to use more than 25% rye flour.
The second one is that Sourdough bread with rye flour in it needs a really long time to rest, 24 hours or more. As absurd as it might sound, it’s actually necessary. Rye absorbs a lot of water, and 1 hour in the oven won’t be enough for that water to evaporate, and for the dough to be completely cooked.
If you want to know more about how long you have to wait and see some pictures I made of a rye sourdough that has been left to rest enough, and one that hasn’t. You can check out my article: How Long Should I Let My Sourdough Bread Rest? (+Pictures).
7. Slowly Incorporate Different Types of Flour
So whole grain rye flour will get you the sourest taste out of all types of flour. But most people don’t make their first starters out of whole wheat flour. But you don’t have to make a whole new starter from scratch. What you can do instead is to slightly incorporate the flour that you want to use, right now I will use rye flour as an example.
If you were to suddenly change the flour that you are using, your starter will need some time to adjust to the new flour, so you won’t be able to use it for some time.
What you can do instead is to replace some of the flour that you typically use with rye flour.
So for example, if you feed your starter 50 grams of white flour, you can change that to 5 grams of rye and 45 grams of white flour. And the next day 10 grams of wheat and 40 grams of white flour.
This way your starter will have an easier time adjusting to the new flour, and it won’t need as much time to get back to full strength.
8. Mix Your Starter Really Well
It’s really important to mix your starter really well when feeding it, if you don’t do it the water and the flour won’t incorporate properly and the starter will take longer to break the nutrients down. But there is another reason to mix things a little more if you want an extra sour sourdough bread.
Oxygen is essential for the development of acetic acid, without a proper supply of oxygen the bacteria won’t be able to make as much acid as they would have otherwise. And while the oxygen in the air surrounding the jar will help, giving the starter a really good stir will incorporate more oxygen in the starter, which will be able to produce more acid.
9. Give the Starter Time to Mature
A starter that doesn’t even have one month won’t be able to produce the same sourness as a mature starter will.
A mature starter had fermented for longer and had enough time to develop its taste, while a fresh starter hasn’t fermented for that long and the sourness hasn’t reached its full potential.
Unfortunately, there is no way to speed up the process, you will have to wait for your starter to mature and develop its taste.
If your starter is young you should use some of the other methods described in the article to increase the sourness of your bread, until the starter has developed a more intense taste.
10. Keep Your Starter at Low Temperatures
While there is no way to age your starter faster, there is a way to make it ferment for longer, and that is to keep your starter at a lower temperature.
A lower temperature will slow down the fermentation process, so it will develop a sourer taste.
So a few days before baking try keeping your starter in the fridge, this will make it ferment for longer and develop a more sour taste.
11. Use the Starter After Its Peak
The moment you combine your starter with the rest of the ingredients for the bread will significantly change the taste of the bread.
A sourdough starter can be used before it reaches its peak, when it reaches its peak, and after it reaches it, and each option will make the bread have a different level of sourness.
To obtain the sourest taste you should use the starter after it reaches its peak. This is when the bacteria have completely finished eating all the sugar that they could find, and have produced the most acetic acid.
To be sure that you chose the right moment you should use a marker and keep track of how high your starter has risen. The moment you notice that your sourdough has stopped rising and starts to go down, that is the moment you will get the most sourness out of your starter.
If you want to know what other effects this will have on your bread you should check out this article where I give a more in-depth look at the subject and provide detailed photos as well: When Will a Sourdough Starter Reach Its Peak? (With Pictures).
12. Use Warm Water
Most sourdough recipes require you to use warm water. But if you don’t want your sourdough bread to be sour, you should use cold water instead.
Warm water activates the bacteria in the starter quicker, which means that they will have less time to create acetic acid.
A good water temperature, for a sour sourdough bread, is 75°F (18°C). Going too much over this is not recommended.
13. Use Dechlorinated Water
Tap water usually has small amounts of chlorine in it, which has been used to make the water drinkable.
The problem is that those small amounts of chlorine can destroy some of the good bacteria living in the starter. While this won’t completely ruin your dough or your starter, the bacteria will make it have a harder time doing its job.
14. Degas the Sourdough Dough
While the bread is rising, if you want to increase the sourness of your bread, you should stretch the bread and shake it from time to time. This will get rid of the gas in the bread, and move the bacteria around.
This will make your bread sourer because you are helping the bacteria move from one place where they are done consuming the sugar, to a place where they haven’t eaten it.
15. Increase the Duration of the Second Rise
During the second rise it’s not recommended to touch the dough too much, so degassing it is not an option. But what you can do is place the dough in the fridge.
This will slow down the fermentation process, and as a result, the dough will rise slowly, but it will ferment for longer, so the taste will be more sour.
16. Use Sour Salt
A simple thing to do is to use sour salt instead of normal salt when making the dough.
Sour salt is normal salt that has been combined with citric acid. This will increase the acidity of the dough, and produce a more intense sour taste.
17. Use a Small Amount of Starter
This one is a little counterintuitive, but let me explain to you why using smaller quantities of starter will make the bread taste sour.
The role of the starter is to make the rest of the ingredients, in this case, flour, and water, ferment (rise). If you use a big quantity of starter, the dough will ferment quicker, but it won’t ferment for too long. So the bacteria won’t have too much time to consume the sugar and to produce acetic acid.
If you were to use a small amount of starter, the bread will ferment slower, but more efficiently, more of the sugar will be gone, and the bread will develop a more sour taste.
18. Don’t Use Other Levain Agents
A levain is the thing that makes the bread rise, in the case of sourdough bread, it’s the starter. For other types of bread, it can refer to yeast or baking soda.
If you use another levain agent alongside the starter, the bread will most likely rise faster, but the starter won’t be able to fully do its job, so you will have more sugar and less acid, so overall you will have a less sour bread.
19. Use a Preferment
Instead of using a starter for the sourdough, you could use a preferment.
A preferment is a combination of starter with water and flour. Making a preferment is like making the dough for a sourdough bread, and then stoping and using the dough that you made as a starter for another dough.
Doing this will increase the sourness of your bread, as well as its rising power.
20. Use a Solid Starter
Most starter recipes that you will find on the internet are for a wet starter or a 100% hydration starter. This means that you will mix equal amounts of water and flour to make the starter. But this is not the only type of starter that exists.
A solid, or a stiff starter, is a starter that has more flour than water in its composition.
The bacteria in the starter produce two different things that influence the taste, acetic acid, and lactic acid. The acetic acid has a sour taste, while the lactic acid has a milder, slightly sweet taste.
The water in the starter facilitates the production of lactic acid, which is not what you want for a sour taste. What you want is acetic acid.
So the smaller the amount of water that you use in your starter the sourer the starter will be.
21. External Factors
Another important role in the sourness of a sourdough bread is played by external factors, like temperature and humidity.
A low temperature and low humidity will result in sourer bread.
While there are a lot of ways to control the temperature and humidity in our homes, it will still partially be influenced by the weather outside. So a bread that is made on a hot rainy day won’t be as sour as one made on a cold dry day. While the difference is not that major if you really pay attention to the taste of the bread you will definitely notice it.
Final Thoughts
As you can see there are plenty of ways in which you can make your sourdough bread as sour as you want.
While there are a lot of small things that you can do to make your bread sour, it mostly comes down to using the right ingredients, avoiding the bad ones, and keeping your sourdough at a relatively low temperature so that the fermentation process will last longer.
Using all of those tips will make your bread really sour, so it might not be for everyone. This is why I usually bake two loaves, one really sour loaf for me and one that is milder for everybody else. If you want to know how to make sweet-tasting sourdough bread you should check out my article: 21 Ways to Make Sourdough Bread Less Sour Tasting.