# Hydration

forno

I have heard the gurus around here talking about hydration in relation to starters, can someone give me a quick explanation as to how this works.

Is this percentage based on the flour quantity or the starter quantity

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## Replies

gt 2006 July 25

Sourdom,

Excellent explanation. I'm wondering if you could you give an example of how you determine the grams of flour and water in a starter that is not 100%? For example a 55% starter or a 166% starter. I think many folks have trouble with this.

Thanks Gary

Bill44 2006 July 25

Gary, I have designed a starter calculator that I will ask Maedi to put in the calculator section.
It is a calculator for a two stage starter that will let you make any amount, any hydration, and with any combination of flours in it.
Give me a day to pretty it up and write the instructions and I will submit it to Maedi.

gt 2006 July 25

OK Bill thanks, I'll watch for it.

I just wondered in general how you folks determine the flour and water in non 100% starters. I probably should have started a new thread asking the question.

Thanks Gary

Bill44 2006 July 25

Hydration 101.
In a recipe or a starter the flour is considered to be a figure of 100%. Now if you have a starter as in this case at 80% hydration then the figures are flour 100% water 80%. So adding the two together you get a figure of 180.
You have a starter weight of 1000g so divide 1000 by 180 = 5.555555. So multiply 5.555555 x 100(flour) = 555.55g flour, multiply 5.555555 x 80(water) = 444.44. So add the two together as a double check 555.55 + 444.44 = 999.99. Check again if you want (444.44/555.55) x 100 = 80% TA DA!

This is just an example

gt 2006 July 25

OK Bill, thanks again. I understand it and it makes sense to me.

Anyone else do it a different way?

Thanks Gary

SourDom 2006 July 25

thanks Bill for your starter calculator, and for helping with the above.

one of the advantages of 100% hydration starters is that it makes calculations a lot easier!

For a given starter, the "true proportion" of water is going to equal
(Percent hydration)/(percent hydration+100)
(Because the flour is always 100 percent)

therefore a 55% starter will contain 55/155 water

multiply this by the amount of starter that you have

thus for 200g starter
'55% hydration starter' - the weight of water = (55/155)*200 = 71g
'166% hydration starter' - the weight of water = (166/266)*200 = 125g

(subtract the water from the total amount of starter to give you the weight of flour)

cheers
Dom

gt 2006 July 26

Thanks Dom, just wanted to make sure I was getting the right answer. I
find the flour weight first by dividing the starter weight by 1 plus the
hydration percent (in decimal form). Then subtract the flour weight from
the total for the water weight.

Thus for 200g of starter
For 55% starter: Flour = 200/1.55 = 129g, Water = 200 - 129 = 71g
For 166% starter: Flour = 200/2.66 = 75g, Water = 200 - 75 = 125g

This gives the same result as you and Bill get but in a little differnt form.

Thanks Gary

Croc 2006 July 26

[quote="gt"]
Thanks Dom, just wanted to make sure I was getting the right answer. I
find the flour weight first by dividing the starter weight by 1 plus the
hydration percent (in decimal form). Then subtract the flour weight from
the total for the water weight.

Thus for 200g of starter
For 55% starter: Flour = 200/1.55 = 129g, Water = 200 - 129 = 71g
For 166% starter: Flour = 200/2.66 = 75g, Water = 200 - 75 = 125g

This gives the same result as you and Bill get but in a little differnt form.

Thanks Gary
[/quote]

oh that is very nice and clear

rhaazz 2011 March 10

Bill, your math doesn't look like any math I've ever studied.  My understanding is that 100% is "the whole thing."  So, if a dough or a starter is 100% four, then it is ALL flour and no water at all.  (You can increase things by more than 100%, so that you could describe a dough that has doubled in volume as being 200% its original volume, but you couldn't describe a dough at the outset as being more than 100% of anything.)

So, for example, in chemistry, if I mix an 80% solution of something with an equal volume of 100% solution of the same thing,,  I end up with a 90% solution -- NOT a 180% solution.  I've never seen anyone ADD percentages like that.

For another example: if 30% of conservative voters describe themselves as Tea Partyers, and 80% of Tea Partyers would vote for Sarah Palin for president, you would not conclude from that those poll numbers that 110% of  conservatives would vote for Palin.  You would conclude (I think) that 24% of self-described conservatives would vote for Palin (I'm making these numbers up, I actually have no idea how many people describe themselves as Tea Partyers or how strong Palin's support is, I'm just using this as an example.)

My point is, I've never seen anyone ADD two percentages.  You multiply them (in the Palin example, you multiply .3 X .8), or you average them (in the chemistry example).

rhaazz 2011 March 10

Bill, your math doesn't look like any math I've ever studied.  My understanding is that 100% is "the whole thing."  So, if a dough or a starter is 100% four, then it is ALL flour and no water at all.  (You can increase things by more than 100%, so that you could describe a dough that has doubled in volume as being 200% its original volume, but you couldn't describe a dough at the outset as being more than 100% of anything.)

So, for example, in chemistry, if I mix an 80% solution of something with an equal volume of 100% solution of the same thing,,  I end up with a 90% solution -- NOT a 180% solution.  I've never seen anyone ADD percentages like that.

For another example: if 30% of conservative voters describe themselves as Tea Partyers, and 80% of Tea Partyers would vote for Sarah Palin for president, you would not conclude from that those poll numbers that 110% of  conservatives would vote for Palin.  You would conclude (I think) that 24% of self-described conservatives would vote for Palin (I'm making these numbers up, I actually have no idea how many people describe themselves as Tea Partyers or how strong Palin's support is, I'm just using this as an example.)

My point is, I've never seen anyone ADD two percentages.  You multiply them (in the Palin example, you multiply .3 X .8), or you average them (in the chemistry example).

rhaazz 2011 March 10

I understand how important it is to have a high hydration dough, but I don't understand the comments in this forum.

For example,  Croc wrote, " I find the flour weight first by dividing the starter weight by 1 plus the

hydration percent (in decimal form). Then subtract the flour weight from the total for the water weight."

Croc, could you please be more specific? You find the flour weight of WHAT (the starter or the whole dough?)  You divide by 1 + the hydration percent OF WHAT, the starter or the whole dough ? (my recies always start with flour + water +salt + starter, so there is additional water in the dough).  Then you subtract the flour weight of WHAT from the total weight of WHAT?  Sorry to be so clueless but I could really use somehelp. Thank you for your patience.