The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Liquid replacement calculation

sonnyj's picture

Liquid replacement calculation

When using starter in a regular recipe, do you count it as 1 to 1 replacement for water?



dmsnyder's picture

Hi, Sonny.

Regular recipe? That would be sourdough. ;-)

If you are converting a recipe that calls for unnatural leavening, also known as baker's yeast, to one that uses natural leavening, also known as sourdough starter, you should calculate the amount of flour and the amount of water in the starter you plan to use. I assume you are measuring ingredients by weight. So, you already know the hydration level of your starter. If you are not weighing ingredients, I would urge you to start doing so.

Let's say your starter is 100% hydration. This means you have fed it equal weights of water and flour. Let's say you plan on adding 125 gms of starter to your dough as a substitute for the yeast specified in your recipe. That amount of starter would contain 62.5 gms of flour and 62.5 gms of water. If you want to keep exactly the same proportions of flour, water and other ingredients in the recipe, you would decrease the flour and water in the recipe by 62.5 gms each.

Obviously, if your starter is at 50% hydration or 125% hydration, and if you are adding more or less starter, you would adjust the calculation given in the example accordingly.

I hope I understood your question correctly and that my response is sufficiently clear. If not, ask again.


Larry Clark's picture
Larry Clark


David's explanation is right on. Here's a url for a simple baker's percentage calculator. I don't know if it will help you know, but probably will in the future. I use it all the time.



josordoni's picture

Larry, that is just brilliant..


I have been cooking from Jeffrey Hammelman's Bread and I  love his formulas, but sometimes I have a specific amount of starter and want to know how much the other ingredients should be to make a formula - he splits down the starter and the overall quantities but never says what percentage of starter to final dough I should have . 

Since I work in metric, I am using his professional metric amounts and dividing them down to get to a workable home amount already, and the maths to find out how much of my starter I should use is not the easiest thing for this little tool is just perfect and does the job. 




knit1bake1's picture

I've been avoiding asking this for months, but here goes. I normally am not too exact about feeding my culture. I just keep it a little gloppy, not firm. I now have many bread books, and each uses a different texture (if that's the right word) of starter. Glezer, Leader, Lepard, Reinhart whole grain, etc.


How do I adjust or go from what I have to what they have in their books? Undoubtedly this has been covered before, so please direct me to the right place. 



sphealey's picture

=== How do I adjust or go from what I have to what they have in their books? Undoubtedly this has been covered before, so please direct me to the right place. ===

Don't hesitate to ask around here - we love questions. If it has been asked before someone will follow up with a link to the previous discussion.

As one of the super measurement geeks here I am going to offer what for me is a very uncharacteristic procedure: just start with a small amount of your original starter and ignore its original proportions. As a percentage of the final build the original starter can just be ignored (assuming it isn't the consistency of beer or cement).

Let's say you are need some starter from a book that recommends a 60/40 flour/water mixture. Measure out 20 grams of your stater, 60 grams of flour, and 40 grams of water; mix well and leave overnight. The next morning mix that with 120 grams of flour and 80 grams of water and leave for 8 hours.

Keep going that way until you have as much built starter as you need. The larger amount will be close enough to the proportion the recipe recommended as to make no difference and you won't need to do any detailed arithmetic to get there.


Mini Oven's picture
Mini Oven

to do would be to figure out just what your starter is. So next time weigh it, that little amount you want to feed, then weigh the water, then the flour to the consistancy you normally make it. And report back with the bare numbers. It May turn out you already have the right ratios or hydration or water to flour or %.

Mini O