The Fresh Loaf

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Calculation troubles

Andrewjs's picture

Calculation troubles

maybe you fresh loafers Can help me with my pore math skills. 

if you have 215 g of leavin in a final levain build and want to build up to that, how do you caculate that If it's 20 percent starter, 60 % water and 100% flour. In other words how much flour water and starter do you need to total 210 grams. Is there an easy way of calculating that?

drogon's picture

That is, if you want a 100% levian.

So you need 215g of levian. Divide by 5 and get 43. Use 43g of starter then double that 86g flour and the same again, 86g of water, mix, stand and wait a few hours and you have 215g of active levian ready to mix into your dough.

If your starter is 20% of the mix and you have 215g starter then the flour in the final mix is: 20% of X = 215; re-arange and get 215 * 100/20 = 1075g. The water is 60% of that 1075 = 645g.

Normally you'd start with the total flour though, so e.g. 1000g of flour, 20% starter is 200g (and to make that at 100% do the divide by 5 thing and get 40g starter, 80+80 flour + water) and 600g water in the final dough. (don't forget the salt)

Hope that helps...


Andrewjs's picture

ok so let me clerify.. I'm trying to find out how much is in the first leavain build. The 215 is the final leavin build. 

So if 215g at 60% hydration is the starting leavin for the final leavin build how to find out how much water, starter is 20%. It all has to equal 215. If it was calculated like you did, it would be at 100% hydration, but I need it to be at 60%

Andrewjs's picture

im ending with 215, and I'm trying to figure out an easy way to caculate the previous leavin build to get to 215. So 215 is the final levain amount for the 3rd build. Assuming all builds at at the same hyrdation as the formula for the final build. it says previous leavain build, and I'm not sure how to start the formula off. I think he is following Gerard's tripple build leaven, or at least inspiration.


Andrewjs's picture

I'm using a 60% hydration starter and only have a small amount of starter so building to 216 was the part I was having trouble figuring out. 

Thanks for the help!

Elagins's picture

Use the BBGA baker's percentage method instead.

Flour      100%
Water       60%
Levain      20%
TOTAL    180%

If you want 215g of sponge, divide 215 by 1.8

215/1.8 = 119.4 = 100%

Giving the formula:

Flour   120g (=119.4g * 100% - rounded)
Water    72g (=120g * 60%)
Levain   24g (=120g * 20%)
TOTAL 216g (= 120g * 180%)


Stan Ginsberg

Ru007's picture

Didn't know it was that easy !

Andrewjs's picture

so awesome. i will use this math any time  need too now.  Thanks a bunch!

Andrewjs's picture

Figureing its a Gerard's style levain and Iv read other posts from him. I figured it was 60%