The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Ratio Starter to Biga Ingredient

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flournwater's picture

Ratio Starter to Biga Ingredient

I finally got a starter that I'm satisfied with.  It's that Pineapple juice process (which works very well)

Now I need to add some of it to the biga preparation but I haven't the slightest idea of what ratio to use.

Any experienced recommendations appreciated.

dlt123's picture

I've always wondered this also... What I've been doing is weighing out about 4 oz of my starter, then add this to my Soaker or Sponge the day before making my bread.

This has worked for me.   I also use some bread yeast to my loaves to help in the fermenting process during rise.

I will say that my recent SD bread hasn't had that great of SD taste and I'm not happy with my starter, so I think I'll start a new one.

I would also be interested in hearing how others weigh or measure their SD starters in their breads.


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proth5's picture

This is how I was taught and, in fact, what I do.

First, to be nit picky, a biga is the popular name for a firm pre-ferment using commercial yeast, so technically you will not be making a biga.

To make a pre-ferment with a sourdough culture, which I have been taught to call a firm or liquid levain (depending on the hydration):

  1. Know the hydration of your starter.  Yours looks like 100% or more.

  2. Then decide how much flour you want to pre-ferment.  This can be as much or as little as you want, but isusually no more than 33%.  I usually pre-ferment 12% which is on the low end of the range.

  3. Decide on the hydration of your pre-ferment.  For ease in mathematics you may want to keep this at the same hydration as your starter.

  4. Then decide on your innoculation rate.  That is, what percent of the total weight of your pre-ferment will be your starter.  This will depend on the general heath of your starter and the temperature at which your pre-ferment will be maturing.  I use 25% innoculation rate in the winter when my house is quite cool and will reduce the percent to 12.5% in the summer.  So, you must understand how long you will be letting your pre-ferment mature, the temperature, etc.  The first couple of times - you guess.  If you find your pre-ferment over mature you may wish to reduce the innoculation rate.

  5. Now we get out the slide rules.  Let's say that your total formula calls for 40 gms of flour and you wish to pre-ferment 25% of the flour.  Your starter is at 100% hydration and you wish to make a pre-ferment at 100% hydration.  Assume, that whatever starter you put in the pre-ferment will be removed from it to keep the starter going (even if it is not, the amount is likely to be small and we are trying to keep the math simple)  You decide on an innoculation rate of 25%.  The total weight of the flour in your pre-ferment will be (.25* 40gms - 10gms) 10 gms. The weight of the water will be (10*1.00 = 10) 10 gms.  The total weight of your preferment will be 20gms.  The weight of the starter to add will be (.25 *20 = 5) 5 gms.  You will make 25 total gms of the pre-ferment and remove 5 gms after it matures to replace the starter you used.

Of course, you can make the math more complex.  I certainly do, but this is a fairly accurate way to calculate how much starter to use. I did the algebra and worked up a spreadsheet that will calculate how much starter to use at any percent of starter vs pre-ferment hydration and does not require the removal of the starter.  So have others and they are posted in the tools section of these pages.  I thought I would explain the rationale, though

Or, you can just use a good, existing recipe...

Hope this helps.


flournwater's picture

Wow!!  That's the kind of help I was hoping for.

Your information was complete enough for me to develop a spread sheet (I hate doing pencil and paper math any more) and I thank you for the details.  What I truly enjoy about this forum is that no matter what challenge I come up against as a newly obsessed bread maker, there is always someone in the group who can help me advance.

You are absolutely correct; my starter hydration is precisely 100%.

I'm new to this bread making thing and I'm not sure about "biga", "pre-ferment" and other unique terms associated with this culinary craft.  All I know is if I yell "fire" in my neighborhood (I live in the forest) my neighbors don't wait for me to define it beyond that general term.  Inferno, conflagration, etc. are unnecessary descriptors as long as the message received generates the life saving response to run like hell.  Don't misinterpret my comments here as "snarky"; they're not intended to be.  Your explanation of the various terms is helpful and I am now energized to research the terms so I can more clearly describe my circumstances when I have an issue with the making of bread.


proth5's picture

Bread making terms fly fast and loose, it seems.  I work in a field where it is important to be precise in one's terms, so to preserve my sanity I keep my bread baking terms precise. I find it easier to describe things as what they are (pre-ferment is always a portion of the flour fermented before the complete dough is mixed.  100% hydration pre-ferment with commercial yeast tells me exactly what the thing is.  Sponge, biga, poolish - not so much.  You catch my drift...)

Hope your spreadsheet works well for you.  What I liked about understanding this method is that I can bake a recipe, evaluate it, and then decide what factor to change (% of pre-fermented flour, total hydration, etc.) to get the bread to my taste.  Baker's math changed my baking life.  I wish I had learned it sooner...

Happy Baking!


flournwater's picture

Ditto, proth5, the baker's percentages I read about was the turning point for me in making bread that was at least fit for human consumption.  Prior my introduction to these I made some pretty good bricks but not much in the way of good bread.

I am an incurable OC (I seem to control it better as I get older) with a willingness to accept failure only if I have learned something from it.  So bread making was frustrating for me until baker's percentages and a notebook to keep track of what I did differently each time and the result it produced increasing better results.

I spent some time in quality control with an electronics manufacturing company, making controls for the space shuttle, missile defense systems, etc.,  so my professional exposure to accuracy may be similar to yours.  Your approach to the preferment using sourdough starter is helpful.  Thanks again...

jackie9999's picture

Thanks for that proth5 ..I was puzzling over innoculation percentage, your post cleared that up :)