It is weeping liquid in the jar
Updated
The recipe cause
Weeping that starts in the first days is usually a formulation problem, and it is the one that can be fixed for the next batch rather than recovered in this one. The gel formed and then contracted, squeezing liquid out of its own structure.
Too much acid. Acid is what makes pectin set, and past a point it is also what makes the set come apart: the network forms and then releases the water it was holding. This is the far side of the window described on too little acid and it never sets.
The storage cause
Weeping that appears later is usually about where the jars have been rather than what went into them, which means the recipe needs no change at all.
Too warm, or moving. Fluctuation is listed as a cause in its own right, which means a case that spends its days in a hot van and its nights in a cool store is being damaged by the cycle rather than by the peak. That is a distribution problem, and it is on when stock goes off.
Telling the two apart
Timing separates them more reliably than appearance does, which is one more argument for a dated batch log. A jar that wept in week one and a jar that wept in month four need completely different responses, and without a date you cannot tell which you are holding.
| What you see | Which cause |
|---|---|
| Every jar in the batch weeps | Recipe: the acid |
| Some jars weep and others do not | Storage: where they have been |
That split is the only diagnostic available after the fact, and it is worth recording batch and destination for exactly this reason.