Someone asked Sahl bin Sa'd Radiyallahu 'Anhu "Did Rasulullah Sallailahu 'Alayhi Wasallam ever eat bread made of white (fine) flour?" He replied:
White flour may not have come before Rasulullah Sallailahu 'Alayhi Wasallam till his last days". The questioner then asked: "Did you people use sieved flour in the time of Rasulullah Sallailahu 'Alayhi Wasallam?" (DE)
English reference (DE): Book 24, Hadith 138 (DE)
Arabic reference (DE): Book 25, Hadith 146 (DE)