If you read bread recipes, you'll often see a reference to the 'Hydration level' of the bread. This can be confusing and you totter on the edge where baking and science meet.
Please don't be put off. It's really easy to understand and will give you a good indication as to what the results of all your efforts are likely to be.
'Hydration' refers to the ratio of flour to water. It's often referred to as the 'Bakers Percentage'.
OK - a simple formula.
If you think of your weight of flour as being 100% then the amount of water you add creates the 'Hydration level'.
So, let's say that you add 500 gms of flour and we call that the 100% baseline.
We want a hydration level of...70%. So 70% of the weight of flour has to be liquid.
70% of 500 gms is 350 ml of water.
I never work this out, I simply turn sideways and shout 'Alexa, what's 70% of 500?' She's much quicker than me. But you can use more conventional means, if you wish.
So, what does the hydration level do?
As a rule of thumb:
- the wetter the dough, the higher the hydration level. The wetter the dough, the more sticky it is and the more difficult it is to handle.
- the dryer the dough, the lower the hydration level. The dryer the dough, the more firm it is and the easier it is to handle.
Higher hydration levels give you a thinner crust, a more open crumb and a softer texture.
Starting out, I found a lower hydration level easier to manage. The dough behaved itself and was easier to form. With time and practise, I was able to handle a wetter dough and so was able to increase the hydration level.
If you're using wholemeal or whole grain flours (spelt, rye, khorasan, etc.) then you need to factor in that these flours absorb the liquid slightly more than normal strong white or strong brown flour. Hydration levels need to increase by 5 - 10%
Here's a simple chart:
In my sourdough recipe, I'm working at 70% hydration. I'd only increase the hydration if I decided to make wholemeal or wholegrain sourdough.
For my normal strongwhite flour non-sourdough mix - I also work around the 70 - 75% hydration levels. However, if I'm introducing other 'dry' ingredients then I might adjust accordingly. The dough will be stickier. but if I flour the board a little more, I can usually handle it without too much difficulty. However, to be honest, I don't find it makes a substantial difference.
If you're making your own sourdough starter, then you should also be aware that a stiff starter usually contains less water (lower hydration) and therefore produces more acetic acid. This tends to transfer to the bread as that 'slightly vinegar taste' that many people like.
If you're not so keen on the taste...and I'm not....then make your starter a little wetter / looser. That way, it'll contribute to a more open crumb while not being quite so 'sour'.
Don't worry if you lose track of the hydration level of your starter....it's pretty easy to guess by eye.
I've just brought my starter out of the fridge for a sourdough bake tomorrow. I've decanted 150 gms of starter into a jar and added 120 ml of water to 100 gm of flour. Tomorrow I'll have 370 gms of starter that will be quite loose and probably somewhere about 90% hydration. That'll be fine.
Tomorrow, I'll measure the flour and water out as though I'm starting from scratch and add the starter as an additional product. I know the hydration level of the starter, so I don't need to factor it in to the formula.
Here's a table that might help.
Happy Baking....
