Is it possible to use soy meal, like you buy at the grain elevator to feed
cows, in place of soy flour in a pollen substitute?  I can only find soy
flour at the local health food store, and they want $1.45 per pound,
whereas I can buy soy meal at the elevator for around $8.00 for 50
pounds, quite a savings, assuming it can be used for feeding bees.
 
As I understand it`the soy meal is what's left over after extracting the oil.
It has been pressed and heated.   The Hive and the Honeybee mentions
feeding it, but not in detail.  The individual particles in the soy meal seem
too large for a bee, so it would have to be milled, somehow.
 
Where do people purchase brewers yeast at a reasonable price?  Again
I can only find it at the health food store for $5.29 per pound.  Is there
somewhere it can be ordered in bulk?
 
I've also seen mention that people add powdered milk to their pollen
substitute.  The Hive and the Honey Bee mentions that lactose might be
toxic to bees.  Any thoughts?