The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Confused about using pre-ferment

Juergen's picture

Confused about using pre-ferment

Hi guys, I've been hanging around here for some time but this first forum post. I'm a little confused on how to use a poolish. To be more exact; is the poolish an integral part of a recipe or is it a distinct ingredient (and should be treated as such)?

Let's say I'm making a simple French style boule by using a poolish. The poolish that I made is 100% flour, 100% water and 0,5% yeast. I then like to add this to my final dough which should be 100% flour, 60% water 1,5% yeast and 2% salt. I want to make a 50/50 ratio dough (50% poolish, 50% final dough). Can I just proceed by adding the poolish to the final dough, or should I adjust the final dough so ALL dough will eventually be 100% flour, 60% water 1,5% yeast and 2% salt ratio? In other words, do I have to take the make-up of the poolish into account when making the final dough, or can I just proceed by making the final dough as if it were a one-step direct dough and than just add the poolish to it?

For those who own a copy of Peter Reinhart's great book "the breadbaker's apprentice", he discusses this issue on page 44 but I'm still confused. I hope you guys can help me out.

proth5's picture

go to On the menu bar select "Bread" and from the drop down that should appear select "Formula Formatting" - in the text body where it says click "here" - click there.

This is a much better explanation than I could give you in a few brief sentence.

But to give a sound bite - a pre ferment represents a percentage of the flour in total formula.  Normally we start with an overall formula, decide on the percentage of flour to be pre fermented, the hydration of the pre ferment, and any additional ingredients to be included in the pre ferment.  This is subtracted from the overall formula to  provide two columns to be scaled - the pre ferment and the final dough.  The pre ferment is an ingredient in the final dough.

I sound rather tedious when I repeat this, but knowing the precentage of flour to be pre fermented is the glue that holds this system together. People have told me I am wrong about this, but I hold firm. The numbers that you have given me above do not allow me to tell you anything.  If you had only included the percentage of the flour to be pre fermented I could have given an answer to your specific question...

Please look at the Bread Bakers Guild of America technical article.  They have been very generous (well, they are bakers...) to provide this to non members and re enforces their mission as one of education (as well as some really good parties!)

Good luck!

Juergen's picture

Thank you for your reply. My intention was to have a dough consisting of 600 gram of flour. I used 300 gram in the poolish and another 300 gram in the final dough, this makes 600 gram (50/50 ratio of poolish and final dough). My final dough however, was made as if it were a one-step direct dough with a hydration level of 60%. To this the poolish was added. I now realize that by doing so, ALL dough combined had a higher hydration level than 60% (since the 300 gram poolish had a 100% hydration level to begin with). I guess this is the mistake I made?

proth5's picture

that was your mistake.

Seriously - read the article.  Once you wrap your mind around the technique for calculating formulas with pre ferments it seems so easy and so logical that you wonder why you ever did it any other way...

Juergen's picture

Thanks again. I'll definitely read the article, I sometimes have this odd habit of making things far more complicated than they really are (and that's not limited to bread baking only ;-)

thomaschacon's picture
thomaschacon (not verified)

The Bread Bakers Guild format is intimidating at first. Once you learn how to use it, however, you won't go back to your previous method. It requires more than a rudimentary understanding of baker's percentages (and basic math and Excel), but your post suggests you know enough to proceed.

If you need help with baker's percentages, the Guild published an article titled "The Demystifying of Baker’s Percentage". It helped me a lot and it might help you too.

It speaks to your original question when it says, "For clarity, we suggest not calculating the percentages for the final dough because they can be misleading and confusing, especially for those new to baker's percentages. They will not give you an accurate picture of the total hydration in the formula, and they will give you a skewed picture of the amount of salt and yeast in the total formula."

It goes on to say exactly what proth5 said above: "Knowing (a) the percentages for the total formula and (b) the percentage of total flour fermented in the preferment are the most important pieces of information to understanding and evaluating the formula."

Here's what your 600 g recipe (50% poolish) above would look like using the Bread Bakers Guild format (I did it quickly, but I think correctly).

Larger image here:

(Note that you won't find a column of gram weights in the original specification–only kilogram weights–but I find it helps when small quantities of dough are involved.)

Yevgenia's picture

 proth5, thank you for the link. It's very useful. 

proth5's picture

You are welcome for the reference.

You know, the reason I push this technical article on people is not because I have been plied with sufficient amounts of goodies to make me a BBGA fanatic.

It is because it is simple, elegant, and actually increases understanding.  With the exception of the "soakers are hydration neutral" business (and I can see the theoretical basis for that, although the practice is difficult), once you wrap your mind around the standards a lot of the questions about pre ferments can easily be answered.  While there is absolutely nothing wrong with doing the whole thing in your head as some posters below do, being disciplined in the use of the given format makes things easier in the long run.  "Gee, I like this bread, but it seems a little flabby when I shape it, I wonder what a firm pre ferment would do?"   "I like this formula, now how do I convert it to sourdough?" "This is great with a poolish - wonder what it would be like with the pre ferment split between a poolish and a levain?" The calculations are the work of an instant.

Those of you who are math wizards - I've done complex spreadsheets to calculate formulas and nothing works better or faster than the one supplied by the BBGA.  Some of their simplifying assumptions come from years of real baking and make sense once you see them in that context.

In practice, I have been able to sit down and write acceptable formulas with nothing but that format and a little experience with baking.  The "overall formula" column being (as mentioned below) the place to start.  (The percentage of the flour to be pre fermented being the next spot - "Gee, I like this formula, but I think it needs a bit more flavor - how can I make it with a pre ferment?")  Frankly, when I see a formula without that, my eyes glaze over just a bit - how am I to understand the totality of the dough?  I can't (well, yes, of course I could, I could do all the math myself and compute the overall dough.)

On these pages very few would dispute that weighing ingredients results in a "better" bread (more consistent, just plain faster to do, whatever "better" might mean) but somehow I find myself a bit defensive when I suggest the BBGA standard formula formatting.  There is something about it that brings out the rebel in people.  Perhaps in a few years this will be as much common wisdom as using scales.  Let my experience with Imperial measures vs metric be a lesson to you.  I use Imperial measures because I spent many, many years using them and I can visually equate this pile of flour with a pound and this pile of sugar with ounces (and I'm quite good at it in Imperial and still hopeless at it in metric), but for a beginning baker I always recommend that they should learn metric (not because it is more accurate, but because you don't need special scales that show ounces in decimals...) Jump on the bandwagon early.  Learn the good technique first, so you don't have to unlearn a lesser one.

I baked just fine before I heard of baker's percents and this style of formula writing.  I bake just fine now - except now I bake with a better understanding and more range.  I wish I had seen this standard 50 years ago...

OK, off the soapbox.  This time I couldn't help myself.


gerhard's picture

Maybe what I do is wrong but what I have been doing for the preferment is use half the total flour, all the water and all the yeast.  Let that bubble up for a few hours and then add the remainder of the flour, any fat or oil and salt.  It seems to work with small batches and the result are consistent.


G-man's picture

Here's what mine generally looks like:

300g flour

300g water

0.5% yeast. This is the poolish.

Added to poolish:

200g flour



500g total flour, 300g total water. That's about 60% hydration.

subfuscpersona's picture

it's always good to follow standards.

henryruczynski's picture


Everything that proth5 says is correct

The guild site gives you so much information and if you tune in to the BBGA, you will

be a happier person.

Here is a “simple” note I made up for you to follow as example.

Start from left and go right until you get final dough.

This is, to me the best way to present a formula.

You immediately know what percentage of ingredients are being used:


”oh yeah, he’s making this dough with all white flour – 100%;  70 % hydration

the salt is 2% of the flour weight and his instant yeast is 0.007 (which if you multiply times three, would give you 2% fresh yeast)...”


Looking at this recipe, you know how much of the flour is being  prefermented (30%)

and for how long. (usually amount of yeast will give you an indication of ferment time)

The rest of a recipe would give you mix time, dough temp number of folds

proof time, oven temp and bake time and so on.



Juergen's picture

All of the replies have been so helpful and your simple note has really been an eye-opener for me. Based on your note I made a simple Excel-type spreadsheet in Open Office for a very simple sourdough bread which I will make later today. Nothing fancy, all white flour @ 60% hydration. The sourdough part will be 25% of the total and has a 100 hydration level. I hope it works out but I'm glad to be on the right track now because of all of your help.

Juergen's picture

Thanks everyone for such detailed feedback, you've been very helpful. Since I only recentely started my bread baking journey, I'm still a novice. Help like this is very much appreciated.