The science behind sourdough

Ever wondered what the two key factors are which most influence the flavour and fermentation power of your sourdough?

[@davidstump8231]

This is the best explanation of sourdough starters I have seen. Thank you so much!

[@PuratosGroup]

Thank you very much!

[@marjankrebelj4007]

The last graph was the missing piece in my puzzle. Thank you!

[@sweatybrau7256]

This is a really good explanation in very simple terms. Thank you.

[@philippeclavier4190]

Simple, to the point and at the same time explains all you need to know. Thank you!

[@pufarinu]

Amazing ! I didn't know that the viscosity will influence the taste ! Many thanks !

[@csababota8267]

Simply the best explanation of the topic.

[@tilemaxos7]

excellent explanation of temperatures and why they affecting the taste of sourdough! Thank you very much!

[@michaelmayo3127]

Great video, it was just like science class all over again, I'm glad that I pay attention.I completely understood the chemistry. A very informative video, best explanation ever.

[@mariammaatouk179]

Thank you so much for explaining this so simply!

[@calogeros]

This is excellent! Bravo Maestro!

[@nonchalanthabibi5394]

Explained in such a beautiful illustrating manner

[@geurthakfoort]

Thanks a lot for sharing this knowledge! It will help me a lot in my sourdough journey!

[@dapursecimit2613]

Thank you for putting things into simplistic illustration....

[@gutterhunk]

this is the breakthrough I needed to understand my sourdough baking adventure.

[@boazgubany3403]

Thx for this video, very informative.

[@ConnerGaming1208]

i was working on a science project and this was the best vid i saw by far

[@JamesKunst]

Wow! Thank you very much for this explanation.

[@marisv2113]

Very good explanation!

[@akabeka2352]

Nice amazing explanation , thanks .

[@nicholascotardo3795]

very nice explanation :) ! greetings from an italian baker.

[@tasosmenelaou4204]

Excellent video. The best I have ever seen about sourdough starter. But please explain what happens when you have stiff starter and higher temperature 30-35 or liquid starter and lower temperature 20-25 degrees. Thanks for your answer.

[@sheilahinaut162]

thank you! so helpful!

[@justicetoledo7990]

very clear ....thank you

[@Ricki4shoes]

Thank you !!

[@magnustorque5528]

Really some very good added information there re: Ph levels, temp and consistency of starter in terms of realizing different flavors via homo / hetero LAB.

[@VictorCharlesEvans]

Thank you for your time and effort in a very well explained lecture of sourdough starters! Warmest regards!

[@DANVIIL]

Great info. I love the tang, so I need a stiffer starter and need to keep it in the 20-25C range.

[@SparkyOne549]

I use a stiff starter at 70F, no sour. I can hold it over my head, nothing comes out.

[@kevinu.k.7042]

Great video For those of us home bakers who use higher hydration leavens we can simply take a small amount of starter and feed it up to volume again instead of using the bath method. Effectively diluting the acids. It would be great if you went into acidity more including protease and dough degradation from acidity. Thanks for a great video.

[@gul9578]

Can we have more of those lessons please !!!!!!! THANK YOU

[@supersosiska]

Great explanation! What I lack is the explanation regarding: what should I do when my sourdough starter becomes too acidic? Tgabks in advance!

[@trooper3262]

Thank you

[@jessicajones8605]

Omg his voice is Amazing! I must stay focused

[@bellajaid]

Thanks. I should try a lower temp. I'll also check out the "bath" since I keep neglecting my starter 🤣

[@mrt3317]

Does the temperature affect the amount of yeast produced in the fermentation, or is the Co2 making it more lively on the cooler temperatures?

[@higicir1030]

👍

[@user-sm9ko3dq4m]

Your diagram with the four quadrants at the end of thevideo is very interesting! I´m (home)baking in a very warm climate. Day temperatures are typically between 30 and 35 ºC. So there`s a lot of swinging between de the cold in the fridge and the heat outside. Poor yeasts and bacteria, undergoing all those schocks! I just started tinkering with stiffer starters (Instead of my normal 100% hydration starter). How would you fill in the quadrant (high temperature x stiff starter). Thanks! Do you know of persons / sources who have experience serious knowledge on sourgdough baking in tropical climates? Thanks / Dankjewel (Jan van der Weijst, Guatemala).

[@johannesroos2242]

Muito bom !!!!

[@devbachu7072]

Nice

[@DavidSchindel]

Excellent explanation, thanks! How will the use of rye flour versus whole wheat versus bread flour affect this process? Will it just change the rate of the process? Thanks again!

[@annapeppard2400]

It won't make a difference, I made starter with grapes about 24 yrs ago

[@grantcalloway571]

So it’s better to keep a stiff dry starter? My starter I think is too acidic even when I feed it daily or every twelve hours. What do you recommend?

[@PaulCikatricis]

What happens in the other two quadrants - top right and bottom left?

[@finneh6145]

Lower right and upper left are the extremes. Everything else is in between so it will produce some acetic acid, but not as much as lower right.

[@dianel.9703]

Why is a stiff starter better for fermenting enriched breads?

[@jailthejudge]

I wonder what happens to your sourdough starter if you let it mature between 25 and 30 degrees instead of 20 to 25 or 30 to 35 degrees?

[@gastongeorgieff3398]

And wich is the best temp for yeast?

[@ingridgillette5573]

I'm a bit confused! I just saw your interview with the Bread Code and you explained this topic completely the opposite. You said a stiff starter produces less acidic flavor and liquid starter produces a more acidic flavor. Which one is it please? I like a more yeasty less acidic flavor.

[@alexkim7270]

Wow I never knew about that pH4.2. That's why it's called sourdough, and that's why it's important to ferment the starter - to kill bacteria!

[@matthewgiragosian]

I have heard white flour is homofermentive and whole wheat is heterofermentive, therefor you will have trouble developing white dough vs whole wheat. Is this true? Can we find the amount of each bacteria in a flour supplier?

[@dapursecimit2613]

May you do another video on the relation of these microbes to gluten development/destruction... And how yeasts and LAB can symbiotically co-exist.... And how we “engineer” ratio of yeasts and LAB to better produce bread to our liking... Yup... I’m a nerd like that.... ☺️

[@PuratosGroup]

Thanks for sharing. We will consider this topic for upcoming video shootings.

[@oakbal]

Dear Mr. Smedt, what are lower and upper hydration limits for stiff sourdough starter definition? Thanks in advance.

[@PuratosGroup]

Dear Özer, low means probably a hydration of 42-43%, lower than that the flour is not hydrated enough to form a dough. High is around 120%, at these levels the flour is decanting very fast, and a layer of hooch is appearing on the surface. Regards, Karl, the sourdough librarian

[@oakbal]

Dear Karl many thanks for your prompt reply. If we are talking on starter, I am accepting 60% hydrated flour as stiff starter and 100% hydrated as liquid starter. To my best experience 80% is providing a very strong gluten network in starter, especially when it is fed twice or three times. Thank you again for your scientific videos.

[@DostavkadivanovRu]

Thx/ What about stif in 30-35 and liquid in 20-25?

[@sourdoughlibrary4154]

The amount of organic acids produced is higher in a liquid starter compared to a stiff one. What I recommend you is do to the test yourself. Split your starter in 2 parts and ferment at different temperatures. As such you will discover what happens. You can then change the consistency and repeat the test. It would be nice if you do so to comment back. To know is to do, all the best! Karl

[@DostavkadivanovRu]

@@sourdoughlibrary4154 THX a lot

[@nikolaskallianiotis8622]

I have made both sour and mild tasted bread with my liquid (100%) starter. It's all about temperature and fermentation time. Maybe the stiff is easier to produce a more acetic taste in the final bread due to the lower water content (so the solute is tend to be more alkaline) but again, if the temperature/time are not strictly controlled the outcome can be either. It's all about controlling temperature and time, the viscosity isn't the decisive factor.

[@77goanywhere]

So if I have a 100% hydration starter that is kept in the fridge, but I make a Leven from it as the first step to baking, and I use warm water to "wake up" the starter, how will that affect the flavour and "rise" of the bread? I am new at sourdough but I am getting some nice bread already from a 2 week old mother starter.

[@KarlDeSmedt]

Good to hear that you make nice breads. When using warm water you wake up the micro-organisms faster. As such they start to produce organic acids and CO2 rapidly. They thrive best between 20 and 35°C. So a good wake up with warm water (lukewarm) gives them a head start.

[@giuliobontadini]

i missed why the viscosity affects the balance between homofermentative and heterofermentative Lactive Acid Bacterias does anyone know? thanks!

[@KarlDeSmedt]

Good remark. t's mainly their activity. Not their balance. In a liquid starter the micro-organisms act faster and as such the amount of organic acids produced over the same time lapse than in a stiff starter is higher.

[@cristinavindas4514]

Science IS sexy...

[@danielamanu4359]

Hey! it is about wheat or rye flour?:)

[@KarlDeSmedt]

it counts for both. The mechanisms are the same, wheat or rye.

[@luksurias]

so the best temerature for feed and keep going in our kitchen is betwen 20-25 °C ..Thank u.

[@KarlDeSmedt]

There is no best temperature to my opinion. Each sourdough is different. The types of micro-organisms are varying from starter to starter. Some bakers prefer cool temperatures because they are looking for the acidic "tang", others prefer a milder flavour. It all depends what you are looking for in the products you make. Personally my family does not like sour bread. So I'm always feeding my starter a couple of times (3 in general) with max 6 hours in between. And the temperature in my kitchen is 22°C. Take notes of what you do and try to find what you like is best for you.

[@mxgangrel]

Best video ever I only wish you would have linked to the other video you reference about washing your sourdough starter

[@jennydold994]

Bananas Hi! Search for Karl de Smedt (wich is his name) on the internet and you will find lots of info and more videos. 👍🏼 My search was “karl de smedt sourdough” and I got a lot of hits. Yay!

[@zteiw]

kzbin.info/www/bejne/foHdZGl-bK-jj9U

[@alitlweird]

Has anyone ever used rainwater or melted snow for their starter?

[@craigwilson5834]

Where does the yeast and / or bacteria come from? Some people claim that there is wild yeast present in the envrionment that combines with the flour and water. Other claims (like yours) suggest that the microorganisms are present in the flour. How to know which is correct? I assume based on your explanation that bleached flour would not likely work well for starter - correct?

[@PuratosGroup]

Dear Craig, good question. Micro organisms are everywhere. The flour, the jars, the bakery, kitchen even a human body hosts billions of them. In a sourdough the ones that remain present are the ones that are not pathogen, and best adapted to survive in the acid environment. Regards, Karl, the sourdough librarian

[@ginsederp]

Most of the yeast probably comes from the flour. That is why you are advised to bot use bleached flour to start a new starter. Bleached flour doesn't have enough micro fauna in it to properly ferment.

[@bintwang]

i thought you were Ninja from Salty Tales

[@RichardRagan]

So, Tom from Cleveland tells us to keep the sourdough starter, levain, dough, etc between 78-82F. kzbin.info/www/bejne/lYqldKKddphloZI That is in the middle of your ranges: o 30-35C (91F) liquid-like: taste is dairy, yogurt like, creamy o 20-25C (71F) stiff starter: tang, vinegar like, acetic acid taste Q1 - If we do it your way, does that mean we get both taste profiles, neither, or something else? Q2 - If we proof at 91F, should we expect to proof a shorter time than average? Q3 - If we proof at 71F, should we expect to proof for a longer time than average? (assumption: temperature drives the time it takes to get the starter, levain, dough ready)

[@maurashahar2967]

Hello there! Since you seem to be the first one to understand the chemistry behind sourdough, you might be able to help solve a riddle for me. I have been on a keto diet for the last 4 years and the only thing I really miss, is good bread. My theory (based just on thoughts, mind you...) is that making bread with a sourdough starter and letting it rise for a long period of time, should lower the sugar content and the quantity of carbohydrates. Am I just kidding myself or is there anything right in this theory? Thanks for any answer you can supply.

[@joshuatanyongsheng]

The longer you let the sourdough ferment, the more the yeast and bacteria consume the sugars, which will then be processed to alcohol(ethanol) and co2. However when the dough is undergoing baking, these alcohol gets evaporated, so you're half right. When making a sour dough bread, the sourdough starter will be mixed with alot more new flour, to form a dough. Even though the yeast feeds on this new flour, there will still be plenty of carbohydrates left when the bread is baked. So unless you're going for only for a slice of sourdough, it will probably exceed the 25g-50g of carbs per day limit on your keto. That being said, a sourdough will contain lesser carbs then softer breads like brioche because they have add sugar, milk and eggs in the process.

[@maurashahar2967]

Joshua Tan thank you so much for taking the time to reply! I finally have an answer and will know how to treat my cravings for real bread...!

[@SparkyOne549]

My boyfriend has diabetes 2. He cannot eat sourdough, it causes a major spike in his blood sugar, just like regular bread that he can’t eat. The longest proof I did, was 5 days cold restart, it still blew up his blood sugar numbers.

[@grantshalks7338]

This is very confusing: you only mention the viscosity in the summary without any pre-explanation… could you clarify please.

[@KarlDeSmedt]

Sorry about the confusion. In starters with higher amounts of water the micro-organisms are going to work faster. As such acidification goes at a higher speed than in a stiff starter where the water quantity is much lower.

[@grantshalks7338]

@@KarlDeSmedt Many thanks Karl, I will review this 😉👍

[@BixbyConsequence]

My sourdough organisms have to satisfy themselves with room temperature.