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RE: Compensating for Humidity

"Allen Cohn" <allen@cohnzone.com>
Sat, 10 Nov 2007 09:59:18 -0800
v107.n033.5
Hi Dan,

Very interesting analysis, but I think your numbers are *slightly* 
off (not enough to alter your point).

In the "average" case

1209 g average moisture flour X 87.5% solids in average moisture = 
1058 g solids

If we solve backwards

1058 g solids / 85% solids in wet flour = 1245 g wet flour

Difference is 36 g or 3%.

So add 36 g flour and subtract 36 g water from your formula.

Having said all that, I still suspect that this business of adjusting 
for humidity is more of an "old husbands' tale" as MikeA would say. 
My theory is that most/many of these humidity theories were developed 
by people measuring flour by volume as opposed to weight. And my 
informal tests in baking classes show that batch-to-batch differences 
when measuring by volume dwarf that 3% figure.

Allen

PS: The "true" hydration of your bread can be calculated as:

1209 g flour X 13.5% = 151 g water
1209 g flour X 65% add in water % = 786 g water

Total water 937 g.

Total "true" hydration = 937/1058 = 88.6%