The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

How to increase yesat population in sourdough starter

Gabicmacola's picture
Gabicmacola

How to increase yesat population in sourdough starter

Hey everyone! Would you have thoughts on how to increase yeast population in sourdough starters? My starter is active and looks healthy, but takes too long to rise at a very warm temperature (around 30°C). Therefore, my doughs also rise very slowly. That way, because my flour options are all all-purpose flour, the dough starts degrading before it is done fermenting. But... Opposed to that, I have made test with the dough chilled, kept at 26°C the whole process, and tests adding more starter in the recipes–The same happened. I suppose my starter has an unbalanced amout of bacteria over yeast. So, I'd like to hear your opinion on  how to rebalance my levain; on how to increase yeast population and decrease bacteria's to make it rise much faster.

DanAyo's picture
DanAyo

Hi Gabic, we can help you with this.

Please reply with your feed ratio and the time it takes for your starter to rise to maximum height and then just begin to recede. If you can post closeup images of your matured starter, that would help.

Danny

Gabicmacola's picture
Gabicmacola

I feed at 7am 1-2-2, at 2pm 1-2-2 and at 9pm 1-5-5. I keep it inside a cooler with a frozen water bottle at 24-27°C (It's been a hot summer!🥵). Everytime time I feed it, it's usually about to peak, around 95% fully risen. Takes aprox. 30min past feeding time to start falling back. This is a picture of this morning before feeding.

DanAyo's picture
DanAyo

Your starter looks good to me. Is it 25C in your house or in the cooler?

Does your starter rise like that during the day time feedings?

What formula or recipe are you using for your bread and what are the fermentation times (how long)?

Gabicmacola's picture
Gabicmacola

In the cooler. RT at my house is around 30°C, wich is kinda funny, because my starter takes approximately the same time to peak when it's outside the cooler, maybe half an hour earlier. You see that doesn't seem right, don't you? Haha...  It does rise like that, yes. Perhaps 5 to 10% less, but I'd say most os the times it rises equally.

I've tried several formulas. Mostly 20% WW, the rest AP flour. Or all AP flour. Have tried hydrations from 70% to 78%. Nothing seems to change fermentation speed. I bulk for about 5 hours, wich is the maximum time any flour I have can handle almost OK. Then shape and cold retard.

DanAyo's picture
DanAyo

Gabic, I read your other post trying to find a clue that might help us. Your starter looks good.

It is obvious from reading your 2 post that you have researched sourdough baking and are very diligent to learn... If you are willing to work with us, we'll stick with you until you succeed.

  • Is there a bakery near you that you could ask to purchase some of their best flour?
  • The suggestion on the other post to reduce the hydration was an excellent one. 68% hydration would be a good place to start.
  • If you want to work together to work this out, specific details are best. How large a dough would you like to mix? With that weight we can make specific suggestions.

The spreadsheet below is a working example for a 500 gram dough. You could use this for a test. More Levain is not going to solve your problem. If you do decide to try this, make sure you document to process (write down times, etc) and take closeup pictures at important stages of the bake. For example, when you stop the BF, and things like temperature, etc..

Danny

Gabicmacola's picture
Gabicmacola

Hello! I would appreciate your help on this, thank you very much! This morning a did a test similar to what you suggested here:

95% good quality AP flour (that I got from a bakery that imports Italian flour; it's not sold at our local commerce)

5% WW flour

65% H20

*Flour and water from levain weren't included in the calculations)

30% levain

~2,2% salt

Results were very good! My guess is 1) Ok, my levain could definitely use some improvement! But I don't think it was the major problem. 2) The flour I'd been using probably sucked so much it was loosing gas over the course of fermentation + handling. This time, by the end of BF (40m autolyse - Add levain then add salt - 30m rest - 4S&F 30m apart - 2h rest - pre shape, rest 30m - shape, RT for 30m - Cold retard) dough was nice! 

DanAyo's picture
DanAyo

Fantastic! Post some images of your bread and include a crumb shot.

I am excited to hear that you are making progress. Every baker knows all too well what frustration feels like.

Treat that baker well. Buy some of his bread and develop a relationship with him or her. Commercial artisan bakers use the best flour possible.

Danny

Mr Immortal's picture
Mr Immortal

Hi, Gabi!

 

If you’re willing to try something, I’d like to recommend that you replace your 2pm feeding with a 2pm stirring, not on a permanent basis, just for two days (or more time if you want to further tweak things).  If this works, it should decrease the time it takes your starter to peak after a feeding, and in turn similarly affect the timing of your bulk fermentation.

 

My theory behind stirring is this:  yeasts are relatively immobile, and can only access food sources that are in their immediate vicinity.  Stirring redistributes the yeasts and any uneaten food source, allowing them to consume more food and create larger colonies, which in turn allows you to take a larger inoculation into the next feeding.

After the first stirring, pay close attention to how your starter behaves.  If you get another rise after stirring, it’s showing you that your yeast colonies are indeed increasing due to fermenting more of the food source.  If you do not see an additional rise, it’s telling you that your yeasts had in fact consumed all of the food that your previous feeding had made available, and that your 1:2:2 ratio is simply not providing enough food, in which case it may be time to step it up to 1:3:3 (although this can tend to increase time before peak)

 

Lastly, if you’re not already doing this, when you do your feedings, after weighing out your starter, water, and flour, mix the starter and water thoroughly before adding the flour.  This allows for a more even distribution of yeasts throughout the newly fed starter, allowing each yeast cell to come into contact with a larger portion of the food source.

 

I hope that something here is of use to you.  Happy baking!

 

 

Gabicmacola's picture
Gabicmacola

Thank you very much for you tip! Actually, I've noticed an extra fermentation when I use a part of my starter as levain for bread before I feed it again: The small portion left in the jar does ferment a bit more after I scrape off the sides of the jar. I'm gonna give your advice a try anyway, so thanks!

phaz's picture
phaz

If ya look back through my posts (sorry but can't remember exactly when) you can find a little write up about stirring - what to look for, what it means, and how it can help ya determine a good feed ratio/schedule. If look for ya but - I'm lazy, and don't know how!! Enjoy!

Gabicmacola's picture
Gabicmacola

I HAVE TO SAY IT: IT WORKED!

I did it this afternoon. At 2pm, starter looked right at peak, then I stirred it and it got back to what it looked like when I first fed it in the morning. Then, this evening, about 5 hours later, when I checked, it HAD MORE THAN DOUBLED. I can't believe how simple the answer was! I think I'm gonna stick to doing this for a couple day to see what happens. Thank you so much 👌🏻👌🏻👌🏻👍🏻👍🏻👍🏻😁

Mr Immortal's picture
Mr Immortal

Glad that it worked!  The real test is going to be in a day or three, when we see if the increase in yeast colony size leads to a faster and stronger rise in both your starter and your loaf.

 

Fingers crossed!

Gabicmacola's picture
Gabicmacola

So... I don't know what happened! Could you help me?

On day 1 doing this, I stirred my starter at 2PM. Fed it at 7Pm 1-4-4 and it fermented superfast! Almost doubled in just 2 hours at RT (about 30°C). Then, I stirred it and put it in my cooler box. On the next morning, at 5am, it had quadrupled! That'd never happen before!!

So I tried doing the same on the next day. But on day 2 I stirred a couple of times through the day to see what would happen and it fermented Everytime I dit it. At least double. But... After that, here's is what happened: it seemed to start loosing that vibrant life. When I fed it at 7PM again, it barely rose on those 2 hours at RT. The next morning, after spending the night at 25-28°C, it only tripled. 

Then, during the day, it seemed to rise very slowly again. So I stirred in the afternoon and it kept fermenting at the same speed. After feeding at 7PM, again, it pretty much didn't rise at RT, this time for 3 hours. 

What could have happened? What is your theory on why it had a sudden explosion of fermentation and then, even though it kept fermenting everytime it was stirred, that super growth never came around again?

Here is what is looked like in the morning after the day I began doing this:

 

phaz's picture
phaz

How old is this starter? I ask cuz if it's less than a month old it so it may have reached maturity. Kinda sounds like it. If it's older, something else may be happening. But, you have been changing things a bit. Might be good to stick with a set routine for a couple and see what happens. Enjoy!

Gabicmacola's picture
Gabicmacola

It Is at least 3 months old. Maybe more

Today it leavened a bread I made very nicely! But I have to make a new experiment, because today's bread had lots of sugar in it from the raisins and the water I soaked them in that I used as the base water for the dough.

Also, OK, it appears to be fine to ferment bread. But it gets in my head: Why won't it rise as much as it did two days ago again? I just wish to know why I can't replicate those results. If I could, it WOULD be more efficient to ferment my doughs. That's what I'm looking for now: Why did only quadruple once (What might have happened)?

phaz's picture
phaz

Yeah, the yeast really likes sugar. But, I'd say you don't have any problem, so keep on going. The true test is if it makes bread you like, and it does. 

Doubling/tripling - forget about it. It'll change on ya from time to time anyway. As long as it's growing within a reasonable length of time and not falling flat, you'll be good. 

I will add, there's a lot of room in bread making. By that I mean everything doesn't always (or ever) have to be exact to make good bread. I usually start late at night and am too tired to do much. I throw a bunch of stuff in a bowl, mix it, toss it in the fridge till the next day. Take it out next night, cook it. Just like I'm doing now (almost done proofing)! Enjoy!

Mr Immortal's picture
Mr Immortal

I agree with what Phaz says.  Bread baking can be, at times, a very imprecise science.  Sometimes “It Works!” is more important than “How Does It Work?”

 

Once you fall into a regular feeding schedule, your starter will behave much more predictably.  Just keep in mind that even “predictability” can fluctuate a great deal depending on a wide variety of factors, many of which we have no control over.  

I’m glad to hear that your starter is working out for you, and helping you bake delicious bread!  I’m sure that someone here will be able to give you a more scientific explanation for why your starter is behaving the way it is, but this one’s a “head-scratcher” to me.