In electric mixer, using dough hook, add milk and yeast. Add in flour and salt. Mix until incorporated, scraping bowl. Add eggs one at a time, scraping and incorporating each time. Add sugar. Beat on medium for three minutes. Reduce to low speed. Add butter one piece at a time. Increase to medium speed. Beat 7 minutes. Cover with plastic wrap and proof (sit) one hour. Uncover. Deflate. Refrigerate.
Deflate dough every half hour for 2 hours. Cover and chill overnight.
Butter and flour 3 loaf pans. Divide dough into 3 pieces. Divide each piece into four and shape into log and line loaf pan. Cover pans and proof (sit) until double about two hours.