Is there such a thing as flour that yeast can't eat?

a.j.m's picture

 So I have a nice vigorous culture, that I keep in the refrigerator and take out every few days, double with equal weight of whole wheat and water, put half straight back in the 'fridge, and make family bread with the other half.  Works fine, nice bread.    I've been doing this for quite a while.  This culture is healthy and doubles or even triples in six to eight hours.  It's about a year and a half hold.


But my bread-eaters would like a change, and especially would like occasionally a lighter bread with mostly white flour.  So, I tried upping the white flour proportion, and got... pleasant loaves.  But not light or white enough.  And somehow the dough didn't seem to be rising as well.   So... I decided to "rebuild" my starter culture using just white flour.  (Or rather, start a new one, and keep the old one – good call, that!)  I mixed up as usual (150g cold wet starter, 75g warmish water, 75g flour), but fed with just the white flour I usually bake with.  It rose like about 1/4 and stopped.   Hmm, I thought, I guess that culture really doesn't like white flour... let's hope that in a few days of feeding we'll get to a new yeasty communities that does. 


So pour away half, feed again.  12 hours later, nothing.  A few bubbles.


Pour away half, feed again.  Wait 24 hours this time.  Nothing.  A few tiny tiny bubbles on the top.  Still basically 1 cup of nice white flour and water.


Pour away half, feed again.  Wait 24 hours again.  Nothing!    This is wierd, because it seems that the original healthy culture couldn't contribute anything that likes white flour.


Pour away half, feed again, plus a dollop of the whole-wheat starter which meanwhile has eagerly more than doubled despite waiting in the fridge.  12 hours later, nothing.  Not even bubbles.


OK, so my question: can flour have some additive or other property that inhibits yeast from growing in it?


FWIW here's what it says on the flour bag: "Unbleached Flour.  Enriched Pre-Sifted All-Purpose Flour. Ingredients: white flour (contains wheat), niacin, iron, ascorbic acid, thiamine mononitrate, alpha amylase, riboflavin, folic acid, contains wheat gluten".  A long list, but AFAIK those are all pretty standard additives in Canada (and compatible with the designation "unbleached").


 (Or am I just impatient?  I always had such success with the whole-wheat-fed culture that perhaps I should just wait like 2 days between feedings and two weeks for fermentation to start?)


120 users have voted.


rossnroller 2010 December 10

1. It's possible you're underfeeding your starter. Try a proportion of 1:2 starter to flour/water, instead of your current 1:1 (eg: 75g starter, 75g water, 75g flour).

2. If your starter is active, 24 hours between feeds is too long if you're planning to bake with it. 12 hours is the max you should wait between feeds, and even less if your room temperature is warm.

It does sometimes take a bit of time for a starter to adapt to a new flour, but within a few feeds it should be back to full leavening health.


Karniecoops's picture
Karniecoops 2010 December 11

It is curious.  I have 3 starters living in my fridge - 100% rye at 130% hydration, liquid "white" starter 100% hydration that has mostly white (AP) flour and sometimes a bit of wholemeal and/or rye in it, sometimes just straight white, and a stiff stafter 50% hydration with similar variable flour make up to liquid.  However I did just start off with one white 100% hydration starter and the others have been "born" from this, I never really had any problem switching them over that I recall.  I did once forget to save some white starter and just created another one from my rye starter, and I don't recall it throwing it's toys out of the cot because of its new diet!  Maybe I was just lucky?

Instead of feeding your lovely WM starter white (AP) flour, why don't you progressively wean if off wholemeal (but keep some of the healthy WM starter as is).  Perhaps start with 20% AP and 80% WM, then each feed up the AP and decrease the WM until it's all AP?  Maybe you scared the bejesus out of it? (don't know if I can say that on the web!  Oh well, have ;o) Sorry Maedi!).

And I agree with Ross, feed it every 12 hours rather than 24 hourly.

Do let us know what you do and how you get on.

a.j.m's picture
a.j.m 2010 December 12

 Well, it's two days later and the situation is substantially the same.  e.g. last night I fed 75g of the previous culture with 75g of warm water and 75g of AP flour - third feeding since last posting.  it was 220ml on the side of the glass.  this morning (11 hours later) it's 300ml, and some tiny bubbles on the top and inside. it is slightly sour and has a pleasant rather mild smell.  it's fermenting, ok, but hardly at all, which is why i still wonder if the flour is somehow suppressing healthy yeast.


the other possibility is that with AP flour the temperature is more important.  My WM starter raises dough at any temperature, it seems!  in winter like now the kitchen goes down to about 62F overnight. I lleave loaves to rise in a slightly warmed oven that cools to about 65F by morning, and there I've been leaving this sluggish AP flour culture, too.  Perhaps it needs needs to be over 70 to get going.


karniecoops, thanks for the suggestion (progressive weaning).  My current procedure, by now, has reduced to trying to capture a new starter from plain white AP flour.  If it fails, i'll try your procedure next.  Obviously if I'm going to make sourdough from this brand of flour I have to somehow get a starter that can digest it!  

LeadDog's picture
LeadDog 2010 December 12

 I have done as Karnie has in the past just switch flours and never had a problem with the starter working just fine.  Recently I made a new starter from 5 different whole grain flours and my causal observation is that that starter doesn't like white flour.  I have even taken my blend of 5 flour and combined it with white flour and feed my starter with this blend.  The starter still doesn't perform with white flour as other starters have in the past.  My conclusion is that this starter likes whole grain flours a lot better than white flour.

Karniecoops's picture
Karniecoops 2010 December 12

I have noticed a similar thing too LD.  In the past if my white starter seemed a bit sluggish I'd give it a bit of rye or WM flour and it would have a nice little boost!  I think perhaps having part of the bran in the whole grain flours is a lot more exciting to eat than just sifted out no bran white flour.

AJM, why don't you just try adding a bit of WM flour to you newly white starter and see if that perks him up?


a.j.m's picture
a.j.m 2010 December 12

The current situation is : after 4 hours at a higher temp (just under 80F, i.e. in the oven with the light on) the level has gone up about 25%.  (This is 100% wet starter 1/3 of which was the previous 8-hour lot.)  Better rise than any before, so I'll keep the experiment going and save Karnie's two good ideas for the next round.


My goal, after all, was to make bread from mostly white AP flour -- so I need a starter that likes it.  Otherwise when I start the first fermentation of the whole dough. it will just sit there and I'll waste a couple kilos of flour instead of only a few hundred g.  (This has happened before.)  I'm hoping to get a yeasty community going that really wants to live on AP flour.



rossnroller 2010 December 12

[quote=a.j.m] I'm hoping to get a yeasty community going that really wants to live on AP flour.



And I'm sure you will, a.j.m. - just a matter of persisting.

a.j.m's picture
a.j.m 2010 December 13

 Well, last night I mixed it up again, 'cept this time (because there were lots of bubbles although it had risen less than 1/4) I decided to make it into a "stiff" mix, that is 2:1 flour:water instead of 1:1, so 75g of the prev. mix + 65g water + 160g flour.


This rose from just under 1 cup to 2 1/2 cups in 10 hours.   Perhaps it can be used now... but it's -very- sharp, and instead of the intriging sharp beery smell I associate with my starter, its smell and taste are sour and slightly gluey (it's hard to describe smell in words...).  Hmm, trying to decide if further building is in order or try to make bread with it.  I think I'll feed it for another couple of days in this dry form.    

saccharomyces 2010 December 13

It's understandable that your firm starter conversion is of a different character than your previous 100% hydration starter. In regards to expansion, a firm starter is going to show more activity - I think due to the additional flour giving the starter more of a structure in which to trap CO2 and thus rise. My 100% hydration white starter almost doesn't rise at all, but rather just bubbles with life. Some of the same starter used in a firm conversion (~60% hydration) more than doubles with every feeding. But, as you've noticed, some of the traits have changed, specifically smell: much less sweet, yeasty, and earthy - more tart, almost chemical-laden (from the trapped gasses?). Reason being: firm starters are better habitats for bacteria, so the usual microorganism population shifts in that direction; because those lactobacilli give rise to more acids, the starter becomes more...pungent.

But bake with it and you should find it to be effective and flavorful - more sourdough.

a.j.m's picture
a.j.m 2010 December 13

 Dear saccaromyces, thanks! for an explanation that fits so well with my experience with all AP-flour starter, both wet and stiff.    I will bake with it and see.   But I'm hoping for a nice fluffy rise of white bread (that was the point, after all) and my experience in the past was a very disappointing, flat, sour bake.   (And my wife the other breadmaker around here is just about to put in the oven 3 loverly soft white pillows, raised with instant yeast and no kneading -- I'm jealous!)


So, sacc., do you find the white starter (wet or stiff) gives a good 100%+ rise without slackening?  Me, I've never been able to control the slackening of free-form sourdough loaves very well; they take so long to rise that they're always three times as wide as they are high.

saccharomyces 2010 December 13

 Maybe your past experiences have been marred due to the use of your whole-wheat starter in a refined flour sponge? Your ravenous beasties found abundant, readily-digestible starches available, consuming them quickly and thus leading to loaf collapse (over-proofing) before you could get 'em in the oven. So one variable affecting your loaf loftiness could be timing: an over-proofed loaf won't have the oven spring that leads to an open crumb structure. To better control the timing of the secondary fermentation (after the loaves are shaped), you might try refrigerating the loaves after shaping (be wary of moisture, off-flavors, etc. the fridge might throw at you). Some people score and bake right out of the fridge, although I often allow for some warm-up time to ensure adequate rising (it's a slippery slope though!).


Another variable that could lead to your slackened loaves could be the means by which you shape your loaves and then allow them to rise. If your shaping technique needs work, I would suggest watching a skilled baker shape (preferably in person, but youtube has resources available). Search this very forum for some tutorials, too! And when they're shaped and ready to rise, they need to be supported. Depending on the shape, you'll need a basket or banneton (or a bowl/collinder with a tea towel) or a couche cloth or similar means of containment so that the loaf rises how you intend it to without distorting its shape.


Hope that helps! Maybe a stepping-off point for some more inquiries and research? Good luck!

a.j.m's picture
a.j.m 2010 December 19

I have now a starter culture whose behaviour is predictable and which is strong enough to work.   It uses "mostly" white AP flour, but (following karniecoop's suggestion above) I have been feeding it and growing it with a dash (about 10% by weight) of whole wheat.  Perhaps over time it will need less.   I've used it three times.


This culture is much more sensitive than the whole-wheat-fed culture. Ferments quicker and falls quicker and won't work unless I use it at exactly the right time.   As saccharomyces guessed, I've overproofed loaves with a starter like this in the past.  Now I know that success with the whole-wheat bread has been in large part because it sours more slowly and holds longer, so I can more freely pick the time to do the next step.   This fussy starter is only gonna be usable once a week, given my work schedule.


Thanks for all your helps.

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