Can Someone Help Me with My Baker's Math?

[minas6907]

Hey Everyone!

I was trying to figure out the hydration of the basic country loaf in Tartine Bread. The book states on page 48 that the country loaf is 75% hydration, but I dont think thats really accurate since half of the water contained in the leaven is not accounted for in that number. It would be a 75% hydration loaf if the leaven itself was at 75% hyd, but its at 100%.

So how would I figure out the true hydration of this loaf? For those who may not have the book, the loaf contains 200g leaven (100% hydration) 750 g. Water and 1000 g. Flour.

When I first read in the book that its a 75% hydration loaf it sort of caught my attention because of the starter, but then my curiosity was peaked even more when I read this one star review of the book on Amazon which says in part:

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"the discussion of bakers percents and the listed percents do not add up correctly with the amounts in the formula. The total hydration of his basic country bread is off by the amount of the leavan. The total amount of flour is also off by the amount of the flour in the leavan. I wonder if he really understands bakers percent math. Small mistakes are one thing but any professional baker would be or should be embarrassed by this interpretation of bakers percent math. A new baker will gain nothing useful by the confusion created on pages 47) para 1. and page 48. In addition the percent for salt is shown to be 2%, which is a common ratio for that ingredient but then since the flour in the leavan isn't included in the total flour, the amount shown in under the salt column is off by 10%. That mistake won't ruin the bread but, the instructor/author should stay true to the universally accepted use of Bakers Math."

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So while I love the book and dont think it deserves one star, the reviewer has a point, so that just got me thinking. If anyone can help I'd appreciate it, when I've tried to solve it I ran out of brain power :-(

[Blether]

If 200g leaven = 100g flour + 100g water,

then the totals are 750g + 100g water = 850g; and 100g + 1000g flour = 1100g

and the hydration is 850g/1100g = 77.3%.

[minas6907]

Huh. That's easier then I was thinking. Thanks for the math help Blether