Differences in WW Flours - King Arthur WW vs Bobs Red Mill Stone Ground WW Flour
I took a sourdough class years ago and my teacher said that he always suggested we use KA Bread Flour, but did NOT suggest we use KA WW flour. Something to do with the way it is processed. I have always used 15% BRM Stone ground WW flour and 85% KA bread flour in my recipe, but recently, I was teaching my dad how to make sourdough bread and he only had KA WW flour, so we used it. I noticed 2 things. The WW flour was very visible in the dough, it looked almost speckled. Also, the dough was much wetter than it is when I use BRM WW Flour. I know it could be some other variable that made it wet, but I have made thousands of loaves so I know I didn't change anything other than the Whole Wheat Flour brand. I also recently read that 1 cup of BRM weighs152 g and KA WW weighed 113 g. Both measurements taken directly from their respective sites. That is a dramatic difference. Any idea why? BRM advertises their flour is stone ground, but KA does not. Could the wet dough I experfienced be because the KA flour was not absorbing the water because it was lacking something? Super curious.
Is the KA flour noticeably coarser or finer than the BRM flour? A coarser flour has larger particles that will take longer to absorb the liquid. It will still hold as much water, assuming that protein content is about the same, but you will need to allow for a longer autolyse time for the flour to fully hydrate. And a coarser flour will make a dough that looks more speckled than will a flour with a finer grind.
Are the flours both made from red wheat, or both made from white wheat, or is one from red wheat and the other from white wheat? This could affect the dough appearance, if you are comparing a flour made from red wheat with a flour made from white wheat. Not much else is affected (other than flavor) so long as both flours are equivalent in protein content.
I can't speak to the posted weight per cup since I have no idea how each company fills a cup for measurement purposes. The bigger issue is that you are using the same weight of each flour. If you are using cups for measuring, you might well be putting a different quantity of flour in the dough even though you don't intend to do so.
Paul
Those were my thoughts. I'll have to tell him to let it autolyse longer next time. And no, I never use cups. Weights only
KA's packaging for "white whole wheat" flour says it is stone-ground, but not for the standard "whole wheat" flour. I don't have a bag of KA WW to check, but my bag of white WW says it's 28g per 1/4 cup, which is 112g / cup, about the same as what you report above.
"BRM" - is that Bob's Rd Mill? 52g / cup seems unusually large, 38g per 1/4 cup, but I see that's what their package says. I haven't baked with this flour, but If the density number is accurate, your hydration using the KA flour would be much higher than you expect, based on the weight of the flour, if you measured by cups instead of by weight.
TomP
It is true that BRM and KAB process the flour differently: KAB's WW flour is processed in a roller mill instead of stone-ground. I don't know whether this makes a difference; particle size may be more important. Both flours are milled from hard red wheat.
I have used both flours and my impression of the BRM WW is that it is a little coarser than the KAB. I currently have some BRM WW but I don't have any KAB WW to compare side-by-side. I wouldn't put much stock in the density values reported for the two flours. If you're measuring by weight, then it shouldn't matter.
There is possibly another difference between the flours. BRM states the protein content (only gluten-forming? not clear) is 13–15%, and KAB's is usually 13–14%. I think the last bag of KAB WW I purchased was 13.2%. If the BRM WW as higher in gluten-forming protein, then, as stated by others, you may notice a difference in hydration.
Another possible variable is humidity. Are the bread and WW flours stored similarly and in similar climates? Moisture content of the flours could vary enough to affect the hydration. With the WW content at 15%, would the effect be that large, or is it some other factor?