3 of 6 tropical records are published. The wall fills in as the season turns.
Acid and pectin both added
Guava has more pectin than any other tropical fruit — enough that a kilo of ripe fruit will thicken to a sliceable block with nothing added. That is not jam; it is pasta de guayaba, eaten in slabs with cheese. The only real decision is how far to reduce it, and that is a number: 78 Brix.
Fresh pineapple contains bromelain, a protein-cutting enzyme that will digest the pectin you add and leave you with a jar of sweet pulp. The enzyme is destroyed by heat, so the fix is simple: cook the fruit for five minutes before the pectin goes anywhere near it.
Ripe mango sits at pH 3.9 to 4.2, which is too high for a reliable set and, more seriously, too high for safe water-bath canning without added acid. Passionfruit fixes both: it lands at pH 2.9 and brings the seeds that make this jam instantly recognisable on the shelf.
Listed newest first by publication date. Guava Paste That Slices, Not Guava Jam That Runs