Tip - Affect of moisture content in flour
Let’s consider 1000g flour with 1% increase in moisture over a comparable baker.
Extra water .01*1000=10g
Original hydration = 65%
Original water = 650g
Flour that has 1% more moisture
Extra 10g water
Less 10g flour
Total flour = 990g
Total water = 660g
An additional 1.7% hydration for every additional 1% of moisture in flour.
Consider this -
- Identical flour is used by 2 different bakers with a moisture content of 15%
- Baker #1 lives in an arid environment and loses 1% moisture
- Baker #2 lives in a humid environment and gains 1% moisture
Considering the same formula above there is a 3.4% variance in hydration.
Percentage of moisture in flour may be increased or decreased at the mill, during transportation, stocked in stores, or in the baker’s home (arid climate vs humid).
Is this reasoning incorrect?
Can anyone improve the wording of this scenario?
Don, aka MTLoaf lives in Montana. He really started me to thinking about the moisture content in the flour. During the Baguette Community Bake he used French T65 . Same brand as myself. There was no way I could mix the dough at his hydration. He claimed it was the variance in local humidity. I also think elevation could have been a scenario in that case also. I live southwest of New Orleans, near the Gulf of Mexico (very humid).
The gist of this post is to stress the importance of evaluating the “feel” of your dough once it has absorbed all of the available water. Until you know your dough, hold back a little water. You may think you can just as easily add more flour. But every other ingredient in your dough is based upon the Total Flour weight. It is best to handle the “feel” of the dough with more or less water.
I know is that if I live in one area (e.g. Colorado Springs), my adjustments will be different than those of a baker living in another area (e.g. New Orleans). Climatic humidity and elevation both lead to adjustments in dough hydration.
I've used the above examples in some of my classes to help students understand how flour moisture content can vary due to environmental influences.
Seasonal swings also affect flour moisture content. Here in northern lower Michigan, we can get big changes in atmospheric humidity, depending on whether the wind is out of the south and carrying moisture from the Gulf of Mexico, or if it is out of the north and dragging a cold, dry air mass down from the arctic. Add in the dehumidifying effects of heating in the winter and the dough may want more water than it does on a humid day in July.
So, yes, flour moisture content matters and will lead to adjustments. Should I plunk down $50-$200 for a moisture meter? A high-volume bakery may find it useful but I don’t think I will. There are enough other variables that I will still need to read the dough and adjust as I go.
This is why I usually try and hold back some of the water in the formula to adjust as needed....except last bake when I stupidly dumped all of it my mixer and ended up with a way too hydrated dough. To make matter worse it was a porridge bread that I used Durum fresh milled instead of Kamut flour and the porridge was wetter than usual.....one of these days I will learn :).
Abe, in theory it is 1.7% difference in hydration per each 1% flour moisture difference, but not in practice.
In practice, drier than 15% moisture content flours require much more water, over 2% per each 1% lack of moisture to obtain good dough consistency, whereas humid, wet flours require much less that 1.7% water per each 1% deviation from 15% to adjust the dough consistency.
Flour moisture does something to flour starches and proteins that affects their performance in dough. It makes dry flours much thirstier than theoretically predicted and moist flour must less water absorbent.
I never have to deal with wet flours at home, really, only with dry and very dry flours, so my rule of thumb is that my flour needs 25-30% more water than in recipes for standard 15% moisture flours.
I think this is the main reason why you need to adjust for dough hydration. Under the scenario you present, and the math is indeed correct by my thinking, you would need to add a bit of flour so the dough gets to the hydration you want. I noticed this when we moved to a condo in early January. It's a dryer environment than our former house and the flour does not have as much retained moisture. I was always having to add a bit of flour for the sourdough recipe in the old home. In our current place, I do not. the measured ingredients have the correct hydration and nothing else is needed.
I know Hammelman mentions this in his book.