December 13, 2019 - 12:31am
Bakers' Percentages... again!
I'm sorry folks, I am bringing up an old topic, but I have searched through the site and forum and internet and not found an answer that works.
How does one calculate the amount of flour and water using bakers' percentages if the total dough weight is knows.
All answers I have found are incorrect because they ignore the salt content. To make this clear, I will use an exaggerated salt content in my example.
- Target Final Dough Weight: 1000g
- Target Final Dough Hydraiton: 80%
- Target Final Douth Salinity: 10%
By working backwards using "goal-seek" functions, I can come up with the final result:
- Flour: 526g
- Water: 421g (80% of 526g)
- Salt: 52.6g (10% of 526g)
But how do I calculate this without having to use goal-seek functions?
I'm tearing my hear out here and would appreciate some help.
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I do it like this in a spreadsheet. I think it's pretty easy to follow. See what you think. In a spreadsheet you just highlight the two water percentages and it adds it for you ie. for total hydration.
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Soul, not sure I understand the question. Are you asking how to determine the amount of flour, water, and salt to reach a certain total dough weight? If that is the question, you would need a math formula-- so assume your hydration was 80 % and your salt was 2 %, then x + (.8 x ) + (.02 x) = total dough weight.
If you solve that equation 1.82 x = dough weight. So if you wanted final dough weight of 1000 grams, divide 1000 by 1.82 and x = 549.5
So flour = 1 x 549.5 = 549,5
Water = .8 x 549.5 = 439.5
Salt = .02 x 549.5 = 11
You do know that when you take it out of the oven, it won't weigh 1,000 grams, because some of the water will have been cooked off. Since the amount of salt is so small, and the loss by moisture is much larger, I assume most bakers don't get tied up in looking at it to this level of detail.
Try this calculator: https://www.bakerybits.co.uk/dough-calculator-bakerybits/
If I'm understanding the question, it would be 1.00 (100% flour) + .80 (80% water) + .10 (10% salt) = 1.90 (190% total).
1000g/1.90 = 526g
The above answer from mikes is correct, to take it one step further for the OP, you add up all your percentages (as above) and get 190%. Take this and multiply by final dough weight to get the amount of flour (as above). Now you use that number as your 100% and multiply all the other percentages by that one.
So:
Flour at 100% = 526g
Water at 80%= 526*.80 = 421g
Salt at 10%=526*.10 = 52.6g
Of course you would really use 2% salt and might have 1% yeast (I usually use less that that, but not a bad number to use) so:
100+80+2+1=183%
1000g*183%=546g of flour
546*80%=437g of water
546*2%=11g of salt
246*1%=5.5g of yeast
You will note that rounding will result in a 999.5g final weight, but that is good enough.
You can see the raw math in the blog entry I wrote for a recent bake:
http://www.thefreshloaf.com/node/61862/10th-tfl-bake-dec-2-2019
It also includes calculating the levain.
Thanks to all you who have answered. “1000/(1+0.8+0.1)” was the answer I was looking for.
To those wondering why I wanted to know this, here’s why:
I want to take some of the guesswork out of my baking. I have a number of bannetons of different sizes, and I know how many grams of dough each can hold for different flour compositions. So if I want to make 3 loaves with, eg, 10% rye and 15% spelt, and I choose to use bannetons A B and C on this day, I know I will need 780 +550 + 1100 grams of dough.
So I just wanted to work out the Total Flour, Water and Salt, as a starting point, using total dough weight as a starting point. Thanks to your help I’ve also now worked out how much starter to use, how much flour and water to add to the levain, and finally how much flour, water and salt to incorporate into the final bulk.
Based on your answers I have now built myself a little app for personal use that works out the grams of ingredients to add at every stage of the process, based on final dough weight, flour composition, and inoculation. It even works out my minimum hydration based on the flour composition.
This will save me tons of time. Thanks.