January 23, 2013 - 10:49am
How is hydration determined?
I know this is probably a very basic question but I see a lot of people reference that they maintain 100% hydration or other percentages. How is this determined?
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I know this is probably a very basic question but I see a lot of people reference that they maintain 100% hydration or other percentages. How is this determined?
Hi crustic,
where a starter is maintained at 100% hydration it simply means that for every 100g of flour in the starter, there is also 100g of water. So if a starter is maintained a 60% hydration, that means for every 100g of flour, you would have 60g water. The first is an example of a liquid starter, the second one is a stiff starter. Each brings its own characteristics to the resulting bread, as they behaver slightly differently during fermentation.
Best wishes
Andy
So, what will be hydration of:
50g "old starter"
100g flour
100g water
Hi mjo5
I maintain 2 starters; the rye starter is maintained at 167% hydration, and the wheat levain is maintained at 60% hydration. So I know what the original hydration of the old starter is. In your example, the old starter should be 100% hydration, so there are 25g flour and 25g water in it. If a starter is maintained with inconsistent levels of hydration, then the water levels in the old starter might be unknown.
Best wishes
Andy
This is going to be close to 100% hydration, but not quite...although probably good enough to be 100% hydration for practical use.
Consider this:
Let's say that 50g of old starter is pretty wet, 170% hydration (fairly common if you feed at equal parts by volume); this means old starter is 18.5g flour + 31.5g water. This would mean your new starter is actually 118.5g flour + 131.5g water = 111% hydration for new starter.
On the opposite end, let's say your old starter is really dry (55% hydration, like bagel dough); that would mean old starter is 32.3g flour and 17.7g water. This would mean your new starter is actually 132.3g flour + 117.7g water = 89% hydration for new starter.
So you can see both are close already. You can also see that after one or two of the same feedings, you'll practically be at 100% hydration. You can speed the process of getting to 100% hydration by just using a smaller amount (25g or so) of old starter, and/or increasing the amount of fresh flour & water you are using to feed (e.g., use 200g of each instead of 100g).
100% hydration means equal weight flour to water, so if you feed it 200g flour, you add 200g water.
If you say you have a "60% hydration dough", then it would be 120g water to 200g flour. And so on.
More on baker's math here.
Cheers,
-Floyd
Hydration equals weight of water divided by weight of flour. 10 oz of water and 15 oz of flour equals 66% hydration (10 divided by 15). 12 oz water and 15 oz flour equals 80% hydration.