Understanding Hydration (Baker's Math) will allow you to make or tweak any pizza dough recipe on the planet!

Hydration 101

Hydration - the process of causing something to absorb water. When it comes to baking, that something is FLOUR! No other ingredient in baking is hydrated. That is why in the process of autolyse, only flour and water should be used. Autolyse is the resting period where flour is allowed to absorb the water before mixing or kneading the dough.

Hydration is based on percentages by weight! Percentages of what? Flour and water, NOTHING ELSE! By definition "percentage" is the rate, number, or amount in each hundred. So, this is where you start, and since it is the flour that will be absorbing the water - FLOUR IS ALWAYS 100! Water is always a percentage of the flour. Now for the easy part, calculating hydration! At least calculating is easy if you use metric weights or gram weights. This is where a kitchen scale becomes invaluable!

Using gram weights, 100g of flour will contain X amount of water - with X being the hydration. Otherwise, a 50% hydration will contain 50g of water for every 100g of flour - or 50/100. A 60% hydration is 60/100. A 70% is 70/100. A 80% is 80/100. What if the amount of water exceeds the amount of flour? The formula does NOT change. For example, I like to use a 160% hydration for my preferments. Or 160g of water for every 100g of flour, 160/100. Flour is ALWAYS 100!

Bread dough contains more than just flour and water. You might ask, what about ingredients such as salt and yeast? Other than flour and water, they are NOT used in calculating hydration. However, their addition and the amounts used are totally arbitrary and are based on either a percentage of flour (Baker's math) or percentage of total weight of flour + water (scientific math). Let it be said here, whichever method you use to calculate "other" ingredients - their amounts will NOT be be used to calculate hydration but they must be used to calculate the total weight of dough.

Let's make some dough using our understanding of hydration. There are only two questions you need to ask yourself - how much dough do you want to make (size of doughball) and at what hydration?

Let's say you want to make 500g of dough at 65% hydration. What we know is for every 100g of flour there will be 65g of water for a total weight of 165g. Divide the total weight of your 500g doughball by 165 and you get 3.03. Multiply the 100g of flour by 3.03 and you get 303g. Subtract the 303g of flour from the 500g and you get the water, 197g.

Folks it is REALLY that simple!

Other ingredients - using typical amounts as a percentage of flour. Typically 2% salt and 1% yeast is used in bread making. Again using 65% hydration, for every 100g of flour there will be 65g water, but now there will also be 2g of salt, and 1g of yeast - for a total weight of 168g. Now if you want to make 500g of dough, you would divide by 168, 500/168=2.98. Times the 100g of flour is 298g, times the 65g of water is 194g, times the 2g of salt is 6g, and times the 1g of yeast is 3. Add it up, but remember we are rounding off to whole numbers. Total 501g!

What about sourdough starters, or any other preferment? They are made of flour and water, so the amounts used in the preferment is easily calculated and subtracted from the total amounts of flour and water in the recipe. For example, a 100% hydration starter will contain 100g of water for every 100g of flour. A stiff starter might contain only 40g of water for every 100g of flour. A preferment may contain as much as 160g of water for every 100g of flour. However all that matters is how much of the preferment you will be using. Using the 500g doughball, I'll give two examples for a 100% starter and a 40% stiff starter. We'll be using 100g of starter! We won't be adding any other ingredients in these examples. Just flour and water!

100g of 100% starter has 50g of flour and 50g of water. 500g of 65% dough has 303g of flour and 197g of water - so you will use

100g of starter

253g of flour (303-50=253)

147g of water (197-50=147)

Next the stiff starter...

100g of 40% stiff starter has 71g of flour and 29g of water - so you will use

100g of starter

232g of flour (303-71=232)

168g of water (197-29=168)

When you know the math, there is no limit to the recipes YOU can create!