just a heads-up. i bought a 10 lb. bag of wheat montana all purpose in the blue bag at wallmart in missouri. the flour is contaminated with grey-dark grey pebble like particles. when crushed with a rolling pin, they form sand like gritty particles. the largest is about 1/8" across. i contacted the customer service at wheat montana and was told they were "flour scale", but in 40 years, i have never encounter this before. my complaint and photo were sent to the compliance manager who never replied. i reported this to fda, but yet no reply. sieve your flour before using.
Don't use the flour! Take it back to WalMart.
The FDA's Inspection Guide is good reading for anyone that bakes.
Wild-Yeast
I use the 10lb bags purchased from Costco here in Montana, and will pay closer attention.