by Son of a Beach » Wed 12 Sep, 2018 9:20 am
Sugar is a preservative (which is why jam (sometimes) lasts so long out of the fridge). Sweetened condensed milk has an enormous amount of sugar, and therefore it can last for quite a long time without refridgeration, even though it's other main ingredient is milk.
I used to use it a lot when I first started bushwalking. I used it for milk/sugar in my tea, and for milk/sugar in my porridge... and often for just squeezing directly into my mouth.
These days, I don't have sugar or milk in my tea, and I have a slightly less disastrous diet, so I don't carry it any more. But if I'm walking with other people who do carry it, I've been known to help them finish off their tubes (only to save them carrying the excess weight, of course).