The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

Starter vs preferments

Baxter_and_bairns's picture

Starter vs preferments

Hi, so I have some questions regarding the use of starters vs preferments. I understand the topic has been discussed at length on the forum, and I feel I've read through most of the threads, but still have questions.

To begin, I understand there's some confusion/misuse of the different terms.

As I understand it and use here, my starter is my "mother" starter that I keep in perpetuity at 1:1 ratio flour to water.

A preferment, to me, is when I take some of my ripe starter, mix with a % of the total flour and water in the final recipe and let it ferment before mixing with the final dough ingredients.

So, with these terms defined as such, my questions:

1) Most of the sourdough recipes I have followed and baked into successful loaves use around 20% (baker's percent) of the 1:1 starter, added directly to the final dough ingredients (+/- an autolyse of the water and flour before adding starter). By definition, using 20% starter leads to a 10% prefermented flour.

But I've seen on here many threads suggesting that 30% prefermented flour is ideal for a good rise. Some of these threads seem a little older, and I'm wondering if people are moving away from thinking this 30% prefermented flour is necessary.

2) Reinhart's San Francisco sourdough formula calls for a large firm intermediate build that is fermented for 4-5hrs and then cold retarded 12hr before mixing into the final dough. I think I calculated the prefermented flour at 40%. My understanding is that increasing the prefermented flour should lead to faster bulk fermentation, and possibly decreased sour. Yet this bread is one of the most sour I've baked. is it because of the cold retard of the firm intermediate levain?

And why would he chose such a large preferment? What other advantages can this convey to a bread?


3) I think I have more questions, but many would likely change based on the answers I get to these, so I'll hold back and see what people have to say.

It seems like the more I read the more confused I get!

Many thanks for your help.

gavinc's picture

I throw a spanner in the works. Don't get hung up on definitions - starter, mother, levain; they are all sourdough cultures with varying percentages of ingredients. I follow Hamelman's method and I will describe it by referencing the below table. The table is a 750-gram dough of Vermont sourdough with whole wheat.

You will note that the seed culture for mixing the levain is removed after the levain is fermented and before the final mix. The amount of pre-fermented flour is stated as 15% and the hydration is 125%. The levain's flour and water are subtracted from the overall formula to give the final mix amounts. This levain is seeded with 20% sourdough and is fermented over about 14 hours at 21C. If my kitchen temperature is 24C I seed the levain with 10% to stay on the 14-hour schedule.

My levain starts out from an 85% hydration stiff rye sourdough. I convert it to 125% hydration white flour levain over two feeds. Although they have very different ingredients and purposes, they are both sourdough cultures. 

This is a VSD with WW baked yesterday. As you can see it has good volume and oven spring.



 EDIT: some preferments are not sourdough but started with commercial yeast;  eg. Biga, Pate Fermentee and Poolish

Baxter_and_bairns's picture

Thank you, very helpful and much to think on! 

mariana's picture


the amount of prefermented flour in bread dough can vary from 5 to 100%. In other words, you can bake a perfectly good bread from starter alone, smply by adding some salt to it . Or you can create a preferment, a sponge with 100% of flour in your formula. 

If it's a starter, then the culture was propagated so that it preserves the microbial culture. And the dough later on is treated as if it was a straight dough without preferment.

If it's a preferment, then the goal is not so much to propagate the microbes,  but to preferment a portion of bread flour and accumulate aroma and acidity, modify gluten, shorten the bulk fermentation time of bread dough, etc. The final bread dough is handled as in typical sponge-dough or poolish-dough methods. More time for preferment and less time or  no time for bulk fermentation.

How much starter or prefermented flour is necessary is entirely dependent on the bread that you are baking. In certain breads there are rules, but those are mostly protected by law or some national traditions of baking that bread , e.g. rules for German rye breads will have the 30-40% max rule, they recreate certain styles of breads so that they taste, look and smell certain way.

Home baking is like wild West - anything goes, for as long as you like the process and the result. No rules. So don't try to generalize here, simply follow another person's recipe if you like what they are baking.

I baked Reinhart's San-Fran style sourdough and it wasn't sour. It was incredibly fragrant, amazing bread. Sourness depends on your starter. I baked it with one of the starters I got from, the Bahrain culture and it was to die for, so fragrant. It was clearly a sourdough bread, but not as acidic as true San-Francisco sd from Boudin bakery. 

I never analyzed his reasons for such formula. It is his bread no one else bakes it , and I simply followed the recipe. You can ask him personally, I guess. 


Baxter_and_bairns's picture

So is there a difference in the chemistry of rye vs wheat breads that benefits preferments?

I ask, because most of my wheat doughs I use no preferment: i use my starter directly into the flour and water after the autolyse. This seems to be in line with bakers such as Maurizo (the perfect loaf). But Ginsberg's Rye Baker uses a preferment (he calls them sponges) for almost every bread, even if it's <50% rye. 

I'm starting to tweak recipes and play with them a bit and as I dissect them I sometime struggle to decide what is "essential" in s the steps and what is the baker's preference/tradition.

mariana's picture

Not at all. No difference. Both rye and wheat breads or blended rye-wheat breads can be successfully made by straight dough methods. No difference from the same breads made by sponge-dough methods. You will get the same bread. 

In professional baking, you get a formula (100% flour, such and such % salt, oil, sugar, etc.) and you get a number of methods to make dough to choose from, plus unique sizes, shapes, slashing patterns, and baking methods, unique for such and such bread, for example, baguettes and ficelles have the same dough but different shapes and baking goals. One is baked until it loses 20-25% of its weight, another - to 50% reduction. 

You can use any of the methods of making dough, all and any of them will give you the same end result. Some bakeries prefer no-time dough or straight dough methods, other bakeries choose the preferment routine. it is simply a personal choice, depends on how you organize your baking routine, how many shifts you can afford, what makes sense dollar-wise. 

Methods with preferments use a bit less yeast and a bit less starter simply because preferments activate yeast and starter or even propagate some of the yeast cells or bacteria in them. They are the default. If in doubt, or don't know how at all, use the traditional preferment method. From there, once you got the bread right and you know what to aim at taste and aroma-wise, you can start experimenting. Choose your own adventure: with non-traditional preferments, with different kinds of starters, with no-preferment or even no-time dough, etc. 

Rye Baker's recipes offer one choice only, even though most of the recipes in that book are from commercial baking manuals which offer at least 3-4 different methods to make dough for each bread. He could add the straight dough methods and/or no-time dough method for each rye bread formula, but that would make the book bigger. The resulting bread would be absolutely the same, identical. Many roads lead to Rome, you know. Maybe his publisher was against it, I don't know. 

Bread taste is the 'essential' in each recipe. Bake as recommended, notice the final ripe dough acidity and fragrance level and acidity and fragrance of baked bread and then recreate the same but by doing it differently, get to Rome by a different road. For as long as your road brings you to actual Rome, no problem, whether you get there by foot by car, or by plane and shortcuts or long detours are both ok.  

good luck!