So you get a tin of unsweetened condensed milk, and you submerge it in a pan of boiling water, and you leave it for three hours. That’s literally it.
It takes a bit of time, sure, but there’s close to zero effort involved, and you can make a couple of tins at a time, and keep them for a couple of months in the fridge to cheer up impromptu ice cream night, or add to a mug of hot chocolate, or spoon over apple pie …
A few pointers:
1. Any brand is fine. I tested three different brands and couldn’t taste any difference.
2. Make sure the tin is entirely covered. If it gets uncovered, apparently, the pressure will be unequalized and it could explode.
3. Let the caramel cool in the can in the pan of hot water overnight before you open it. Again, apparently it could explode if you release the pressure when it’s hot.