Probably the best written article I’ve read on this subject. All concerning things in the article that Reddit absolutely doesn’t care about. Canning milk? What the fuck.
Edit: I forgot that condensed milk is a thing…wondering if people can make it at home?
Ah yes, the 2018. That's a good vintage. Aromas of pestilence and disease overwhelm the nose. An enticing menagerie of dumpster and botulism coats the palette with a subtle finish of garlic sharts lingering between sips. A pronounced effervescence from years of fermentation leaves a most pleasant mouthfeel. 95/100
I feel like you're one of the people this article is talking about.
Dromio05 showed me several posts he deemed questionable since Reddit took away his own mod badge. For example, this post shares a link to an article about "rebel canners," which Dromio05 argues "gives a public platform to people who openly encourage methods and recipes that are known to be unsafe, like canning milk and open kettle canning." The post is labeled unsafe, but Dromio05 would have removed the link to the article.
Now there's a difference between cooking and canning.
You can safely make sweetened condensed milk in the home kitchen. What you can't do is safely preserve it.
Safe: I want to make a key lime pie tonight, I've got my limes, I've got a pie crust, I've got my eggs...no sweetened condensed milk. Grocery store is closed too. Okay, but I've got milk and sugar, so I'll just mix some sugar and milk in a saucepan and simmer it down, then I'll use that to make my pie tonight.
Unsafe: I'm going to make a big ol' batch of sweetened condensed milk, pour it into mason jars, boil 'em for ten minutes and put them in the cupboard so that it's ready whenever I want a key lime pie.
There's LOTS of stuff that's safe to cook and eat immediately that's not safe to put in jars on the shelf.
It's not all that hard to make; you may have to substitute ordinary limes for key limes as they can be difficult to find in most of the world but you should give it a try.
I think you can make sweetened condensed milk at home but not safely preserve it. Have you noticed there's no shelf stable normal milk? There's no dairy products on the shelf on the Welch's aisle. Even given industrial equipment, the best you can do is evaporated milk.