Pizza Quest Globe

Peter’s Blog, Oct. 1

Written By Peter Reinhart
Sunday, 30 September 2012 Peter's Blog

Here’s the first question that came, from Doc.Dough. He must be a doc, for sure, as it takes a little study to understand the question — but I’ll take a stab at it and then all of you can chime in with comments.

Over on TFL I see lots of people slavishly following very exacting instructions without understanding what the instructions are intended to convey. Perhaps Peter could attempt to articulate the difference between importance and exactness or in some way provide some useful guidance to set expectations a little lower with respect to the behavior of sourdough cultures in the amateur’s kitchen. There is the “you have to do it enough times to have seen it go wrong occasionally” method of teaching, and there is the parametric sensitivity derivatives analytic approach which is fine for the science crowd but pretty useless for the average home baker. Is there a happy medium?

I think the answer is both yes and no. Let me see if I can elaborate: there are dozens of legitimate ways of making and keeping a starter. I have offered to send a file on the subject to anyone who requests it (write to me at to make the request — hundreds of you already have), but the main thing to remember is that a starter is just a medium for the cultivation of wild yeast and lactic acid and acetic acid-forming bacteria. The speed of development and the creation of a hospitable environment for these micro-organisms is partly determined by temperature and also by what organisms are already living in a dormant state on the grain and, to some extent, in the local air.  The biggest mistake I’ve seen in recent times is that people abandon their starter in the early stages (we call it the seed culture stage) because they think it is dead, or it isn’t activating on the same timetable as described in whatever method they are following. Other errors include trying to jump start it with commercial yeast (which is too fragile to survive the acidic conditions and will die and then give off glutathione which wreaks havoc on the gluten), or thinking that their old “mother” starter is no good after sitting in the fridge for months so they throw it out.

It is true that an old starter will turn to mush in the fridge and is not structurally sound enough for using in a loaf, but it only takes an ounce or two of it to re-establish it in a new, strong, viable “mother” starter in a day or two since the micro-organisms are still viable even if the dough itself is spent and chewed up by the acids.

There are a number of theories floating around about why it seems to be taking longer for a new seed culture to get up and running, one of which I discuss in the file referred to above, but I’ve found that the best way to ride out the waiting period is to knead or stir the seed culture, at least twice a day, until it wakes up and starts growing and smelling acidic (starting at phase three in the process; again, this is all spelled out in the file). But the reason for this stirring/kneading technique — and this goes to Doc’s implied question about understanding functionality as well as blindly following instructions — is to prevent invading bacteria and molds from establishing themselves on the surface of the seed culture while we’re waiting for it to establish it’s own strong colony of yeast and bacteria cells. It’s all very dramatic when you look at the dance involved in creating the conditions for this cultivation and symbiosis between yeast and bacteria (usually referred to as LAB, since the “lactic acid bacteria” are the heroes of sourdough bread — at least the “good” bacteria are, the ones who are defending their turf against the moldy ones — along with the wild yeast). Again, too much to spell out here, and I’m sure there will be some counterpoint discussion out there that, I hope, comes in as Comments here. But it’s a start.

Bottom line: there is a lot of science involved in all of this but you don’t have to be a scientist or to know all the science to make killer sourdough bread and to make and keep a mother starter. But it does help to understand the functionality of ingredients and how they affect the drama.  There is a lot of folklore out there on starters, some of it true and some of it simply custom that just happens to work, but almost by accident rather than because of science and function (I’m thinking of things, spoken of as “rules,”  like using onion or potato skins or even wine grapes to get the starter going — yes the starter does work but not because of these things).  Like Doc.Dough asks, can we lower the expectations of needing to know all the science and make it accessible and easy? Yes.

Maybe this is the time to ask all of you, do you have any useful pieces of this puzzle to share that will make sourdough cultivation easy for amateurs or home bakers? Are there any myths you’d like to dispel or get clarification on? Scientists, this is your chance to build some bridges! Let’s get a discussion going….



There is no scientific approach to sourdough (SD) that I have found, we are dealing with living organisms which means it will be affected by practically everything around it.
Tried honey, juice, yoghurt methods with exact measurement etc. and never got a response .. in the end I just gave up and did it ad hoc.
-D1: 1/2dl tap, 2 large Tsp flour (custard texture or there about).
-D2: Dump half, add same as D1.
-D3, D4: Repeat.
-D5: If still nothing, start second batch, toss first if unresponsive on D6.

That was 3 years ago, have 2 healthy rye and wheat cultures that get exercised daily and put to work thrice a week (more if I get cravings :)).

Bottomline: It is impossible to create a ‘fool-proof’ guide to starting and maintaining SD as there are far too many variables in play.
Best way is to write up a piece describing what is what, explaining what SD is, what makes it tick .. people can and will figure it out from there.


Yes and no, Ulf. I agree, conditions can dictate the adjustments each person will need to make and time is very difficult to gauge at first, at least until the starter is well established. But there is some science involved and there are some predictables. But, as you have shown, there is no substitute for using your common sense and finding a way to work around the challenges. Great job!!
Again, for those who want my file on sourdough/wild yeast starters, write to me a and I’ll e-mail it to you.


I am now able to make a wild yeast starter very successfully and consistently. I just moved to a new house (a year and a half ago) and found an old concord grape vine in the back yard. Besides picking a few grapes to munch as I walk past, I’m not really harvesting, but I tried adding a couple ripe grapes to my starter culture last fall et voila, it worked every time. It isn’t super sour, but maybe that would come with more time.

My problem is always that I come back after leaving it for a few days and find a spot of mold on the surface. Is this because I am not stirring it frequently enough? Can I just scoop it off and continue? I have found that glass containers seem to work better in this regard, maybe they are less likely to harbor contaminants.


My kids have said they prefer my commercial yeast breads, and they absolutely object to sourdough pancakes. So for now I am content to re-start a wild yeast start whenever I need it, then keep it going for a few weeks until it becomes inconvenient.

1 2

Add Comment

Pizza Quest Info


Vision Statement

Pizza Quest is a site dedicated to the exploration of artisanship in all forms, wherever we find it, but especially through the literal and metaphorical image of pizza. As we share our own quest for the perfect pizza we invite all of you to join us and share your journeys too. We have discovered that you never know what engaging roads and side paths will reveal themselves on this quest, but we do know that there are many kindred spirits out there, passionate artisans, doing all sorts of amazing things. These are the stories we want to discover, and we invite you to jump on the proverbial bus and join us on this, our never ending pizza quest.

Peter’s Books

American Pie
Artisan Breads Every Day
The Bread Bakers Apprentice
Brother Junipers Bread Book
Crust and Crumb
Whole Grain Breads

...and other books by Peter Reinhart, available on