## Bakers Percentage for Starter

I've been trying to get better at converting my recipes to baker's percentages. I am struggling with how to determine the calculation for how much starter to use to end up with the correct amount of levain for the final dough.

In my recent recipe I took my standard starter and used 3.7 ounces for the seed and added 3 oz. Durum, 2 oz. white rye, 4 oz. bread flour, and 2 oz. Spelt flour. I added 7 oz. water. The overall hydration of the starter is now 64%.

I ended up using 15.5 oz. of levain from the above starter in the final dough. By calculating the following method I determined that this contains 6.01 oz. water, and 9.49% flour.

IW (ingredient weight, water) = IP (Ingredient %) x (TW (total weight) / TP (Total %)

64% x (15.5 /164) = 6 oz.

I then subtracted this from 15.5 to get the flour weight of 9.49 oz.

My question is how do you determine how much seed starter to use to create the 15.5 oz. of levain?

I made almost double the amount I needed since I didn't bother to figure this out originally, but since I would like to give people who want to try my recipe the option of just making enough levain I need to figure this out.

Any help would be appreciated.

Thanks

Ian

It depends on your timing and temperature, but as a rule I figure it takes 12 hrs to grow a bit of starter up to 20X the original weight if it is at 100% hydration and somewhat longer if the hydration is lower. Of course everybody has a different kitchen temperature which varies over the year so your mileage may vary as they say.

To get the 15.5 oz of starter that you want you will need 0.75 oz of seed starter, 6. oz of water and 9.5 oz of flour plus some for the bowl and the scraper. These are awfully small quantities to be measuring so, since it is going to be quite a stiff starter you might mix up a bit extra, knead it to combine, then cut it down to 16 oz or so to ferment.

Personally I have never seen that much difference between a batch made with a stiff starter and one made with a 100% hydration starter. And with a 100% hydration starter you always know that there are equal part of flour and water in whatever amount you use, so calculations are quickly doable in your head. And if you have to train your friends to calculate baker's percentages just to try your recipe, there are likely to be few who actually carry through and make it (which might be OK depending on your intent).

Thanks....How did you figure out the .75 oz of seed starter?

I usually do make extra and don't even try to calculate this, but I figured it was about time I made an attempt to understand it better.

When I post my recipes I usually just give the amounts and don't even mention the bakers percentages so I'm not too worried about that aspect of it.

I'm really just trying to understand this for my own sanity!

Appreciate the help.

Ian

For a 1:10:10 expansion to yield 15.5 oz, the initial inoculation needs to be 1/21 of the final weight. You are doing a 1:12.19:7.80 expansion and 20/(1+.64)=12.19 and 20*.64/(1+.64)=7.80 so you need 1/(1+20/(1+.64) + 20*.64/(1+.64)) of inoculant (note that this is 1/21, the same as it is for a 1:10:10 expansion). The other 20/21 is (within rounding error) in the 12.19 of flour and the 7.80 of water.

The other way to get it is to divide the 15.5 by 10 (to get 1.55) and then by 2 (to get 0.75+) and call 0.75 close enough since you can't measure sticky stuff very well anyway.

Thanks for the help.

See this post on the 1,2,3 approach which works very well and is very straight forward. Essentially the recipe is divided into 6 parts, the first being the ripe starter (100% hydration starter) which is 1/6th or 16.67% of the recipe- a very sound percentage to jumpstart a nice rising loaf. After adding stage 2 (33%) your total is now 50%, the last stage adding the remaining 50%.

So making two loaves of 2 pound each is 907 grams (metric is always easier, buy a scale for $30 that goes up to 6 pounds and work in grams). Your stage 1 starter would be built to 151 grams or about 5.3 oz. That means you would have built up from a couple of tablespoons and have a peak starter at this point plus a little extra that you will use to store until the next bake. The second stage would be double that or 302 grams, or 453 total at this point. Last stage would be remaining giving 907 total when finished. So an easy way and readily scalable. There are recipes posted using this method too. See this post.

http://www.thefreshloaf.com/node/9346/123-easy-formula-sourdough-bread

Type 1,2,3 into the search box above...

Thanks Nick....I will check out the post you suggest.

I have a digital scale but my brain is still used to working in ounces and it's been tough to switch to grams. I guess it is time to start joining the rest of world and use metics.

At least when it comes to breadbaking. Especially if you use a spreadsheet to tweak formulas. And moreover, size. A recipe for bread dough can easily be tweaked to be pizza dough in terms of hydration, and flour composition. I may want 3 pizza doughs at 400 grams each, or I may want two batards at 500 grams each. It gets real easy to change the size or hydration percentage going this route. Lots of free spreadsheets out there and posted at TFL. For all else? I use ounces/pounds! Good luck

See these BBGA standards here: http://www.bbga.org/files//2009FormulaFormattingSPREADS.pdf

Although nothing posted above is wrong in any way, this is a concise and complete explanation of Baker's math and formula formatting.

You do not need to switch to grams to use baker's math - but you may have to find a scale (and there are such scales and I use one) that show ounces in decimals rather than fractions.

Have fun!

Thanks Proth5,

I have read the BBGA write up and it is very useful. I have a pretty good understanding of the process but it was just the seed starter amount I was struggling with.

My scale does have both grams and ounces. If I'm following a recipe in grams I usually will just use the grams. I just need to get myself to start thinking that way all the time.

Ian