How long can I safely keep an opened can of sweetened condensed milk? I have transferred the canned milk to a Tupperware container and I store it in the refrigerator. I am only using about 50-60 mls a day (for hot Vietnamese coffee).
I've kept it for several weeks (maybe as many as 6) with no issues - there's so much sugar in there, it's pretty well preserved. If you're worried you could probably freeze it in small portions and just pull one out each time you want a coffee.