## An easy hydration calculation for sourdough bread.

What is hydration? Bakers refer to the flour weight as 100% and water is a percentage of the total flour. A common misconception is that this sum is a percentage of the dough. It is actually the percentage of all water compared to all the flour.

### The hardest bit is that you will need to do some maths first to put the right numbers in this calculator!

For the flour, **it is all the flour.** So add the flour in your starter/leaven + flour in the formula = TOTAL FLOUR

The water is the water in your starter/leaven + the water from the formula = TOTAL WATER

(This easy to do when your starter is 100% hydration. ie there is the same about of water as there is flour)

# For advanced bakers

This calculator is for advanced bakers, and is useful if you start using a stiff starter or a higher hydration starter.

For this reason, we have developed 2nd advanced sourdough hydration calculators. The first one is a percentage calculator. Simply enter the total weight of flour (including any flour in your starter and/or leaven).

Then as you enter amounts for other ingredients such as salt and water the calculator will tell you the percentages. (Again don’t forget any water in your starter and/or leaven).

The second one is for converting recipes where a different hydration of starter is given to yours. Again we will use my sourdough bread recipe. This time we will assume that although the recipe uses starter at 100% hydration yours is actually 50%.

In this case we add the flour weight on its own, the water as given in the recipe, 300g and our starter, 100g. If we enter 50% hydration for the starter the calculator will work out for you that your total water is 325g, the total flour is 575g, and the hydration is 57%. We can now add water until we get to the required hydration of 63%, and see we need to adjust the recipe to add 339g of water.

Jacob Reach says

Hi, I don’t think the second calculator is fixed. It says my 150 grams of starter has 20 grams worth of water and 130 grams worth of flour at 60% hydration starter. It seems it only works if I enter in 100 grams worth of starter.

Vanessa Kimbell says

Thanks Jacob, we will go through it again and check.

Vanessa Kimbell says

Hello Jacob, I think it is fixed now!

Amir says

Hi

I need papers or references to know more about breads.

I love to bake bread at home

Sincerely

Amir

Chemist

Sarah Smith says

Hi Amir. We have a database of studies relating to sourdough, maybe some of the papers would be of interest to you. You can find it here – https://www.sourdough.co.uk/research/

Donald Evans says

I’m struggling with your calculation of the flour and water content of your 50% hydration starter for the second calculator.

Surely 100 grams of 50% starter contains 67 grams of flour and 33 grams of water and not the 75/25 that you specify which is a 33% hydration

Please forgive me if I an wrong

Vanessa Kimbell says

Hi Donald and thank you for pointing this out. I will get someone to fix this. Vx

Vanessa Kimbell says

I think the second calculator is now fixed! Thank you for pointing it out.

R Purtcher-Wyde says

There seems to be an issue with the calculator, if you add ONLY starter (200g) and set a hydration of 100%, the “total flour” comes up at 175g and total water at 25g.

Vanessa Kimbell says

Hi Ralph, many thanks for pointing this out. I will get someone to fix this. Vx

Vanessa Kimbell says

The second calculator is now fixed! Thank you for pointing it out.