I love experimenting a lot with my jams, jellies, and all other fruit preserves, having tried lots of flavor combinations from more traditionally accepted ones to the possibly unimaginable. I'll have to say that this is my favorite so far.
Breakfast in a bottle, as I'd like to call it, the aroma of sweet ripe mangoes and coffee come together to make for something that smells too inviting and at the same time soothing.
We're basically combining the key elements of a fruit jam in this bowl – a base fruit, sugar, acid in the form of lemon juice, and pectin which occurs naturally in that lemon pith.
Pectin, a substance naturally present in most fruits and is responsible for their structure, is essential if you want to gel up your jams or preserves. Apples, raspberries, oranges, and lemons would be good natural sources of pectin, though it can also be had in powdered form like gelatin. Personally, I wouldn't mind my jam a bit runny so those lemons would be good enough for now.
What makes this mango preserve especially interesting is the addition of powdered coffee, giving it both depth of flavor and a very inviting aroma.
Toss everything thoroughly and spoon the mixture into canning jars, leaving a bit of head clearance that would accommodate the gases inside those bottles as they expand when heated up.
Cooking your preserve in plastic sous vide bags would work equally well. In fact, I did so, having some left but too little to even fill another jar halfway.
Put the lid on, only going for a finger-tight seal. Gases would expand inside the bottle and would eventually need to find their way out. Sealing the bottles too tight would trap those gases inside the bottles, possibly causing them to break in the process.
For the very same reason of allowing those gases a way out of those bottles, it would be advisable to wipe those bottle collars free from any residual fruit mixture.
Assuming that you've picked perfectly ripe mangoes to use for your preserve, 30 minutes in a 194F water bath would be enough cooking.
When the time's up, carefully take the bottles out of the hot water with a pair of tongs and leave them to cool overnight at room temperature before transferring them into the fridge. It would be best to set your bottles on a cooling rack to allow for more even air circulation.
If sealed properly, the high sugar content of jams would likely keep it safe to consume for 18 months up to 2 years. For good practice, I again suggest that you label your jars with expiry dates.