The Fresh Loaf

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Overactive Leaven?

the breadman's picture
the breadman

Overactive Leaven?

While refreshing my leaven I think I may have gotten some commercial yeast in my natural leaven. I used a spoon to stir the leaven that I may have used to measure yeast. It suddenly started tripling in 8-12 hours and has lost some of its acidic character. I did start using an organic flour to refresh the leaven the night before I noticed the explosion in activity and because of my baking my average kitchen temperature has been about 78-80f.

Any ideas on which is more likely? 

Mike Avery's picture
Mike Avery

The amount of rise in a dough or starter is partly determined by the amount of leaven, by the amount of time, and by the strength of the flour and dough development.


I don't think that the starter would care if the flour were organic or conventional, however, the protein content and the amount of stirring you did could affect things. More stirring means more gluten development. I see no reason to get carried away on stirring starters. Just getting the flour wet is good enough.

As to the yeast, Dr. Michael Gaentzle found that bakers yeast added to a healthy sourdough starter will be dead within 2 feedings of the starter. Sourdough is just too acidic for bakers yeast to survive for long. This makes me think that if traces of bakers yeast got into the starter, they won't be hanging around for long. If the new and energetic rises continue, I'd be inclined to think it's the flour. If they stop, I'd think it was the yeast.


Have fun,



andrew_l's picture

I found mine suddenly accelerated when it was around a year old - can't be sure of the exact age, but it had been quite slow, then got faster over a period of time and has now stabilised as a pretty energetic starter. When new, it could easily take 18 hours from making the dough to being ready to bake. Now the active starter, when made into a dough, is ready to bake in about 6 hours.

Perhaps it's just maturing?



the breadman's picture
the breadman

Thanx for responding. My starter is only a few months old - about 3 months. I stir it quite a bit, actually it's Dan Lepard's leaven recipe. It took off so suddenly it scared me. Thank you for the info on the Bakers Yeast, Mike! Looks like it may be the flour.

Again, a hearty thank you!!


staff of life's picture
staff of life

It may be the different flour you used.  It sounds crazy, but the second time I attempted to get a sourdough starter going, I had to pitch it because it was fermenting too quickly!  My first (and successful time) I used an unbleached, non-organic flour, and things went along perfectly.  I decided to use an organic flour the second time around, and within a few hours, it was very bubbly, so I started feeding it.  After feeding it every hour a few times (this is still on the first day) I decided to call it quits.  I suppose it had a very generous amount of natural yeasts.  So, to make a long story short, try switching back to your old flour and see if that helps.