Bashing meat around, mashing, squidging with hands like play doh etc. No wonder it is becoming over mushed, or like corned beef/dog food to some of you, then this mush is solidifying to lumps after such rough treatment. Some even advocate for bags or frozen worms broken up mince bits! 🤢
I haven't tried the sainsbury's beef mince, so I have no idea, but maybe the quality of the meat is the issue here. I often find some places that use a change in packaging as a bonus way to cheapen the product within.
Only too often did the old packaging fail, never kept the product fresh for long, and the flimsy plastic lid was never great for keeping it air-tight.
I buy good quality, low fat percentage steak beef mince, Lidl's is amazing since they have changed to vacuum packed. The meat is so fresh, much better than it ever was in the old trays, and high quality. The sealing in process retains the freshness much better.
I don't make a point of separating it, and I just put it in the pan, just as I used to with the old packaged mince. When I'm gently moving around the pan sautéing, it naturally starts to break up itself (behaves like the old one). I'm not bashing it within an inch of it's life, or concentrating on separating it so much, or no wonder there are issues later. I then just let it gently simmer away on a low heat. It breaks down beautifully and is tender when served.
I wonder if some people are bashing it and frying it on too high of a temp. If you're cutting it up into pieces then blasting with heat, his will cause lumps. I would say either the quality of the meat you're buying is the issue, otherwise it is your prep/cooking method. It isn't the packaging.
It is honestly worth buying it from somewhere else, and to look at the meat quality and fat percentage as well. The quality is definately to blame if it isn't the cooking. I had a bad pack of turkey mince from asda, mushy, poor meat quality, and that sounds a lot like what some of you describe on here.