That is weird. My bag of beet pulp shreds says it's from california. It doesn't have any particles in it.
It's got some molasses in it that turns the water brown but I am guessing that's not what you are refering to, is it?
The molasses used to bother me because I didn't want extra sugar until I learned that 10 pounds of molassed beet pulp only have as much sugar as 3 apples. Onviously I don't feed anywhere near that amount!
Whatever it is glad your system works for you if it's something bothersome. You could always call the 800 number on the bag and ask what it is?