Gram-ma;s Burgers were mostly prepared from Fresh Chuck and Neck Meat Trimings Ground twice to order at the Neighborhood Butcher. they were from Bone-in Butchered meat being hung at the Butchers cooler, averaged 70% to 80% Lean. Then and Now,DELICIOUS. But with the start of Supermarkets, USDA Boxed, Boned, Cryovac, Cuts that included Meat Trimmings, Rough Grind 50/50 [50% fat/50% Lean}to be mixed with Buther department Trimming for Hamburger. This evolved as volume grew, especially because of Fast Food + Giant Chainstore Operations to include Boxed Imported Beef, Bull 90% Visual/Lean, Cow 90% visual/Lean and Steer 90% Visual/Lean all were Frozen or Unfrozen, packed in 60 pound boxes. Shipped from Central/South America, New Zeland, Australia or Canada. This Beef has always been Grass Fed, except for imported trimings from better Grades processed beef. These Meats are thawed, Ground and processed with added fats from Store trimmings to whatever specified, but questionable fat content. Very often these boxed meats are ground up partialy frozen to enhance color and keep appearence red longer in showcase/refrigarator. Ever notice the fluid that suddenly appears in your pan when cooking? Or seems like Fat dripping on your coals that Steams unstead of Sizziling? Now you know why. Your best ground beef will come if you purchase Top Round, Check Boneless or even Stew Meat and grind this twice yourself, or cut into small equal size pieces, chop up in your cusinart type machine, then mix and chop again. You can pre-grind or pre-chop some fat trimmings to mix into your ground beef to enhance flavor. For very good taste and character try grinding up Diaphram or Skirt Steak for a real better tasting treat.