I almost exclusively use the 5lb. chubs of ground chuck that are 80/20. Use them for summer sausage, regular hamburg patties, ground meat for meatballs, etc. I have been to one of the plants where this was produced and it is quite a process - Moyer's in Pa. (MOPAC, Souderton, Pa), one of the largest beef processors in the US. This is the HIGHEST QUALITY ground meat you can purchase on the market today, bar none!
The process starts with the live cattle coming in to the plant, being unloaded and led up 'the stairway to heaven', cattle hand-picked by Moyer employees looking for a plethora of traits, where they are knocked, slit and hung, chains pulling up by the hinds to transport. Once bled (and every drop saved) they are transomed to the gutting/skinning area, then into a nitrogen cooler where they are cooled to 33° in about 30 min., then moved to splitting and quartering, then broke down into subprimals, all trim put on conveyor belts into the grinding room where it's mixed by computer with local lean cattle beef to the exact fat/lean ratio, then into two huge grinders and stuffed into chubs (1,3,5,10,20 and 40lb), flash chilled in another nitrogen cooler, boxed and onto a truck, the whole process taking 4 hours or less. The plant runs 3 7-hour shifts, one hour between each for total equipment teardown and sanitation.
And, that is the secret to their operation. What comes out of their plant is 99.97% free of any bacteria. It is operated just like a hospital to better-than-hospital conditions, all employees dressed in disposable gowns, hats, booties, masks, etc. (which we all were required to don for our visit too!), double air-locks for doors, and so on. By eliminating the bacteria, it extends the shelf life of all their products including their ground beef, from 24 hours in any grocery store or in your home (if you were to grind your own meat) to 45 days! No preservatives or additives, just total elimination of any and all bacteria! This is how those chubs you find in the grocery stores can have a shelf life of 45 days on them (probably about 30 days once recieved into the store, allowing time for transportation and storage).
And, every part of the animal is used, from the blood to all organs to even the fine hairs in their nose and ears (for fine brushes) carefully picked out by hand (one pound of those are worth over $7,000!). Not one thing is wasted, even the fat is rendered on-site into byproducts.
If you ever get the opportunity to tour a plant like that, it's a fantastic experience! Our VP of Meat Operations took us all (about 40 meat managers) on a field trip to the plant (when I was in NY) for a tour of it, and it opened up our eyes into the large scale production of how cattle are processed!