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Help, my wild yeast no longer rising?

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doughdave's picture
doughdave

Help, my wild yeast no longer rising?

This is my first post here.  I'm at a loss as to what has happened, but my firm wild yeast starter (1:1:2, starter:water:flour) is no longer rising when I feed it?  I learned to bake with my mother as a child and, when I left home, she gave me a small piece of her starter.  I've been baking sourdough on my own with it for 3 years and it has always just worked.  I bake 2x a week and store the starter in the fridge or a cool balcony between bakes.  I used to feed it 12 hrs before I bake and it used to rise to double its volume in 8-12 hrs depending on temperature.  At present, I'm trying to revive it with daily feedings of bottled spring water and organic stone-ground flower (it's being kept at 78-79F).  Ordinarily, I just use all-purpose flour and tap water but I'm getting desperate!  I can see bubbles in the bottom of the glass jar but the rise is very slow and less than 25% in volume after 24 hrs.  The smell seems to be less fruity (more sour) and it tastes more acidic than it used to.  I've gone to the library and read a few books but I'm running out of ideas.  It has been 2 weeks of feedings with no real change.  Does anyone have any advise for promoting what is left of my yeast to grow?  Sadly, my mom has dementia so my #1 resource can no longer offer me much help.

arzajac's picture
arzajac

If it's bubbling, then it's not dead.


 


From my limited experience, I believe the universal remedy for a sick starter is feedings.  You say you have been feeding it for two weeks, but how often are you doing it?


I reckon that you should feed it at a 1:1 (starter to flour-and-water paste) ratio once per day until it can double in 12 hours or less, then go down to whatever ratio you usually use. If you use too low a ratio right now, then you are not putting enough yeast into the new batch.  If you just keep adding a little flour (too high of a ratio), you will not provide enough food for them.  Half old and half new should suffice until it starts to become active again.


When that can double in less than 12 hours, feed it twice per day for a week.  Until it can become active again, stir it up three times per day (including feedings) since aeration will help the yeast multiply.


Perhaps this flowchart will help:


http://www.thefreshloaf.com/node/10166/wild-yeast-levain-sourdough-startert-flowchart


 


I'm no expert, but that's what I think makes sense.  Somebody with more experience may have a better idea.


 

Soundman's picture
Soundman

Welcome to TFL, doughdave!


To get a sluggish starter active again I would recommend more frequent feedings, say twice a day, until you see more yeastly activity. Also, I would increase the ratio of flour to starter, so that there was plenty of food for the yeast in your culture. Another thing you might try is temporarily increasing the hydration level. Equal parts of water and flour (1:2:2 or 1:3:3) will allow the yeast to work more quickly. Once your starter is nice and bubbly again you can return to a stiff levain.


Hope this helps!


David

arzajac's picture
arzajac

If the yeast is sluggish, why such a high ratio?


 


I can understand that if the yeast are active, starving them is not a good idea, but in this case, they are not active.  By feeding them so much, you end up discarding them before they can multiply. 


Shouldn't the starter be able to at least double before you suspect underfeeding as being the cause of the problem?


 

doughdave's picture
doughdave


Shouldn't the starter be able to at least double before you suspect underfeeding as being the cause of the problem



That is exactly what I was thinking.  Instead of discarding excess as waste when feeding, I'll start a higher hydration experiment and see what happens with it.

SourdoLady's picture
SourdoLady

What has caused your problem is that you have allowed your starter to become too acidic (pH has gone too low). The yeast cells cannot thrive in this environment and begin to die off.  This can happen if you don't discard enough of the old starter before feeding, if you don't feed often enough, or of sufficient quantity. The appearance of hooch is a good indicator that your starter needs to be fed. When keeping a starter out of the refrigerator, you may need to feed it every 8 hours because it can consume all the nutrients in the flour rather quickly. Another clue that it is time to feed is that the starter will lose some of its gluten and will appear to get more 'runny' in consistency.


I agree with the posters above--increase the hydration until it gets active again, and feed more frequently.

doughdave's picture
doughdave

I agree that the culture has gone slightly acidic.  That is certainly what it smells/tastes like.  What is hooch?

gaaarp's picture
gaaarp

doughdave, hooch is the yellow liquid that accumulates on top of your starter if you let it sit for a while.  If you get any, just stir it back in.

doughdave's picture
doughdave

Thanks for the suggestions.  I'm not convinced that the yeast is running out of food in 24 hrs as there seems to be such little growth.  If the yeast were consuming all the food, wouldn't they be releasing more gas and the starter expanding?  My feeding routine at present is 50g starter, 50g water, 90g all-purpose, 10g rye.  After 2 weeks of feeding, I already feel like I'm wasting a lot.


Here's a photo of what it looks like after 14 hours:


SourdoLady's picture
SourdoLady

You do have lots of bubbles. Why don't you experiment with different techniques and see which works the best for you. Divide out portions of the starter and start two or three, each with a different approach.


Here's what I would do: Take 1 tsp. of the old starter and stir it into 2 T. each of flour and water. Cover and keep in a warm place until it is very bubbly before feeding again. Then feed 1/4 cup each of flour/water.


You don't want to drown your starter with food at this stage, but you do need to get rid of the acid (that's why I suggested starting with only 1 tsp.) Let your starter tell you when it needs more food by watching for the signs--hooch, runny consistency, less bubbly activity, has risen and then fallen, etc.

doughdave's picture
doughdave

The bubbles always appear 8-12 hrs after feeding, but there is very little rise.  I made the mistake of trying to bake with it 2 weeks ago and baked a nice door stop.


Thank you very much for the tips.  I'll give your suggestion a try and report back.

doughdave's picture
doughdave

Just curious, using 1 tsp of the old starter and stir it into 2 tbsp each of flour and water, how long do you think it will take to become bubbly?  I have it at about 75F.

SourdoLady's picture
SourdoLady

There is no way to predict how long it will take. It all depends on how many active yeast cells are already in the original starter. Don't feed it again until it rises and then falls, though. You may have to wait until tomorrow to see good activity. I think 75°F is just fine.

doughdave's picture
doughdave

I started yesterday at 7PM and there was little change by 6AM this morning.  I gave it a stir.  There are now a few bubbles appearing on the surface now (10AM).  Below is its current state:


doughdave's picture
doughdave

I gave it a feeding of 2T flour & 2T water last night (i.e. after 24 hrs).  Here's what it looked like at 6AM this morning.  Still not much rise, but more bubbles.  I'm not sure if it will make much difference, but I started using a new bag (different supplier) of organic flour.  It may just be a coincidence, but I bought my last 10Kg bag of flour just before my yeast stopped rising.



 

Debra Wink's picture
Debra Wink

Dave, your starter looks too liquid to be able to get much rise. What kind of flour are you using, and how are you measuring? Maybe you just need to tighten it up a bit.

Debra Wink's picture
Debra Wink

Can you move it to a cooler spot? 78-79F will favor sour (bacteria) at the expense of lift (yeast). If you can move it to a place about 68 to 72F or so, and feed it each time it peaks (or as soon thereafter as you are able), I think you will see things turn around :-)

Wisecarver's picture
Wisecarver (not verified)

...We're not after all making brew. ;-)
Ooooo lookie, whats that clear substance floating on the top?  hehe

Debra Wink's picture
Debra Wink

But hooch on a starter means the yeast have given up waiting for food and gone back to sleep (while the souring bacteria party on).


Whenever they are active and vigorous, yeast are producing gas... Which churns the mixture and keeps it mixed up... Which keeps the solids from sinking... Which keeps liquid from separating out. I let my starters tell me what they need too, but I hear the message differently ;-)


The quickest way to restore vigor to a sluggish starter is to keep it in active growth until the populations make an adjustment. This will restore the pH, and the desired balance of yeast and bacteria. Cooling a few degrees makes it happen faster. After that, return to a healthy feeding routine :-)

Wisecarver's picture
Wisecarver (not verified)

...Have you experimented with vibratory aeration?
I've been experimenting and the temps you mentioned are what I find works best so far plus some vibration does appear to help.
Maybe the active, beneficial, elements are Disco lovers? :-)

Debra Wink's picture
Debra Wink

Hmm. If they like vibration, they're probably more into rap. I know I can feel that from two cars over at the stop light ;-)


Did you see the episode of Big Bang Theory where the geeks put a mixture of corn starch and water on a plastic wrap-covered subwoofer, and made the blob dance? hillarious.

Soundman's picture
Soundman

Hi Debra,



"the yeast have given up waiting for food and gone back to sleep"



I have read on this site many times about the yeast dying when there's no new food. Is that another myth, or is it just a question of time, and if so, what's the time frame before sleepy yeast go to sleep for good?


I ask because I have been keeping 2 starters on 2 feeding schedules. One is mostly rye and I feed it but once a day. It packs a decent amount of acetic punch, which I sometimes like for the sour it brings to the bread. But some folks say your yeast will die if you only feed once a day. My rye starter has plenty of bubbles, which tells me there are still plenty of yeast. But the naysayers have always made me nervous!


Any help on the subject will be appreciated.


David

Debra Wink's picture
Debra Wink

David, I don't have a difinitive answer for you on the time, or half-life of yeast, but I think it's fairly safe to say that they don't start dying off right away. Microbes have an amazing ability to conserve themselves through tough times by a process of biochemical and/or morphological changes, which shut down cellular machinery so that it's not drawing energy. They may not be able to go on this way forever, but 24 hours certainly isn't much of a stretch.


I think the bigger issue is the kind of environment being created in an underfed starter, and the effect that has on the population dynamics therein. Acetic acid is inhibitory to yeast---even wild yeast. It isn't as sensitive as commercial yeast, but too much can surely slow them down. The other thing is that acids are accumulating, lowering the pH to a point where it could change the species profile. L.s. is more sensitive to low pH than others, so it would likely disappear and a more acid-loving variety would take over.


Certain yeast and bacteria disappear, not so much because they are being killed, but because they fail to thrive. Their growth and reproduction slows or stops, and other more tolerant species take over. In the case of yeast, it may not disappear, but may reduce in numbers or vigor comparative to souring bacteria, and just not provide as much lift as it could.


The bottom line is that if your starter is performing the way you like, then there is no need to change what you are doing. But it's always good to experiment with more frequent feeding to see first-hand what effect it has and what your starter is capable of :-)

Soundman's picture
Soundman

Thanks for your thoughtful and helpful reply, Debra! (And, yes, I laughed at your bringing Raymond Chandler into the discussion.)


I should have added some other information to my questioning post. First, my other starter, my non-rye starter, is wheat-based and gets fed on a 12-hour schedule. So the yeasts therein ought to be similar, if not the same as, and are certainly descendants of, the same ones I got to raise bread 9 months ago for the first time (using the "pineapple solution", good marketing idea by PR).


There have been a million posts on TFL about getting more sour, or less, from sourdough. I started experimenting, created the rye starter, tweaked the feeding cycle, and found it provided a consistently tangy and delicious bread (used together with the wheat-based starter) if that was what I wanted. The wheat starter alone just won't provide the same level of sour anymore, though it did at first. (Maybe that's the downside to refrigeration?) If I want more sour bread, I add to my final levain a percentage of the rye starter, usually 1/3 or less of the total culture used to build the final levain.


Also, I regulate the temperature my rye starter develops at over its 24-hour feeding cycle. Using a modified Detmolder approach, it sits at, variously, approximately 77, 67, and 61 dF over the 24 hours between feedings. I figured that at 61 the whole metabolic parade slowed down enough to prevent a build-up of too much acid, though now I wonder if this may be incorrect. Based on your article, perhaps the cooler temp favors the acid while slowing down the yeast?


You have me thinking now -- that as a result of the increased acidity the yeast in the rye culture are probably quite different from those in the wheat culture. This despite the fact that they both came from the same culture, and branched off based on flour type and feeding cycle. In any case, they seem to be happy and to help in the raising of bread.


So, in the end, the proof of the pudding is in... I am, as a baker, an empiricist at heart (of course!). I base the utility of this approach on the results I get. Fortunately, there doesn't seem to be any animosity between the 2 cultures (no Hatfields and McCoys here). I sometimes add a bit of wheat culture to the rye, which absorbs the former and gets nicely bubbly, either as a result of or in spite of the addition of the "foreign" yeast(s).


Would the presence of different types of yeasts have any qualitative effect on the end product? I.e. would more different strains of yeast help or hinder in any way?


As to the actual real-life end product, I provide a picture of my original recipe "Golden Country Bread" which is the result of the above-mentioned combination of cultures in the final levain, and no commercial yeast, of course. It rises very well, without fail, and has a nice but unobstrusive tang.



As you say, Onward!


David

gaaarp's picture
gaaarp

doughdave, I may be jumping the gun a bit, bit I am sure you will succeed in reviving your starter, so I wanted to make a suggestion.  Since this is an "heirloom" starter that you received from your mother and want to maintain, once you do get it going again, you might want to preserve some of it. 


There are numerous ways to do this.  The easiest is to spread a thin layer of your starter out on parchment or a sheet pan and let it dry.  Then crumble it into a powder and store it in an airtight container.  That way, if you ever let your starter peter out (or if, God forbid, you get away from baking for a while and want to come back), all you have to do is revive the dried starter.

doughdave's picture
doughdave

Just a quick note to say thank you to everyone who replied.  My yeast is back to its old form and now triples in volume in about 6 hours.  Splendid.  Thank you all so much.