Dr Kimbell’s easy hydration calculation for sourdough bread.
When Vanessa teaches people at the Sourdough School to make the healthiest bread in the world, she often explains that hydration is key to getting the most out of flour. Part of the teaching is understanding how water impacts bread and fermentation.
What do we mean by hydration percentage?
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 the percentage of all water compared to all the flour.
The hardest part is that you will need to do some math first to enter the right numbers into 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. The hydration impacts many factorsw hen it comes to your bread.
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.
Judging The Sourdough Category of The Tiptree World Bread Awards
Hello!
I use Jovial Einkorn Flour for my starter, and I do not wish to have any more starters as I have many other starters that is not meant for bread. The jovial einkorn starter is what I think many refer to as a dry starter, and it does not have to fed so much as it is more dough than liquid. It remains on my counter or the fridge as I do not like a super sour bread as a Southern woman in America where we all like sweet things. LOL
If made into a levain, it resembles a wet starter. I have fed it over 10 years now, and I would like to use it with many recipes outside of einkorn flour. To refresh, it is 20 grams of starter, 56 grams of all purpose einkorn and 100 grams of water. I have no idea what hydration percentage this is. Any chance you know? I would like to know if my starter can be adapted to your recipes. Probably with the hydration of my starter, I am aware I will have to adjust water and flour amounts. Just curious on your opinion before I buy your books. Thanks so much!
Hi Amy! Your sourdough starter hydration fed with those ratios would be about 178% hydration (this seems unrealistic given you’ve said that your starter is a dry starter — are you sure you wrote the correct measurements?). And most sourdough starters can be adjusted to suit a recipe, but it’s always a good idea to gradually adjust the ratios over a few feedings rather than just switching right away to avoid shocking your starter. Hope that helps!
Hello!
I checked the amounts, and they are accurate.
https://jovialfoods.com/recipes/create-einkorn-sourdough-starter/
This is the sourdough starter I have used, and I refresh it for a larger batch if you scroll to the bottom where the amounts are listed for that. People have described this as a dry starter as it resembles a ball of dough when you refresh it before it flattens out. Is this not correct?
Also, knowing this, what would your recommendations be? I would prefer to be able to adapt my starter to your recipes rather than changing it, if possible. In the state it is in already, I do not have to feed it all the time. Thanks so much
hi
If there is a soaker in my dough, I add the weight of the dry grain & water ofthe soaker in the calcultion of hydration. Am I doing the correctly?
thak you
Yes, you’d need to include any water or flour incorporated.
The second calculator is wrong, because if I add 830 flour, 550 water and 220 levan, the total dough weigh says, 1500 gm but in fact is 1600 gm. and don’t forget the salt. which should be 1.5% of the flour amount .
I have a suspicion your 2nd calc is still incorrect. Maybe.
I’ve entered 500g flour, 380g water and 120g of starter.
Starter is 100% hydration (so 60g flour and 60g water.
All good except, ‘total flour’ field is showing 620g.
This isn’t possible if my starter only has 60g of flour.
If I’m right the Total Flour should be 560g? (Being 500g dough mix + 60g from starter)
Not sure if this skews your overall hydration calc or not.
Thanks Martin – we will keep looking at it.
Hello Martin, I have checked it again and the figures work for me – I get 560 using your figures. Always good to get feedback though so thank you for that.
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.
Thanks Jacob, we will go through it again and check.
Hello Jacob, I think it is fixed now!
Hi
I need papers or references to know more about breads.
I love to bake bread at home
Sincerely
Amir
Chemist
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/
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
Hi Donald and thank you for pointing this out. I will get someone to fix this. Vx
I think the second calculator is now fixed! Thank you for pointing it out.
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.
Hi Ralph, many thanks for pointing this out. I will get someone to fix this. Vx
The second calculator is now fixed! Thank you for pointing it out.