That's called syneresis and is basically a symptom that the pectin bond has broken down. It's harmless but can be visually unappealing.

Usually it's due to an acid-pectin imbalance with too high a level of acid. But fluctuations in temperature or shaking the jar (jostling it in a box) can also cause it as can over-cooking or too old a pectin.

Some types of pectin are more susceptible to this than others.

You'll have to consider which of these might be an issue with your preserve but regardless, the "fix" would be to stir in the liquid or pour it off. The jelly itself is still fine.

Carol

Thanks so much for your input! The juice is very acidic by itself. What do you think might be best to try? Less sugar? Or a different pectin brand?

More sugar, not less for more water binding. Or a different pectin. Which did you use and how old was it?

But honestly it isn't a major issue. One finds it even in commercial jellies now and then and as Carol said it is simply a matter of stirring it back in and/or avoiding over-exposure to heat as in the car.

Dave

I used a new box of surejell, that's what I find available in the stores here. I know it's just a visual issue, but that matters a lot if you give them away as presents....
Thanks for your answer.

I suppose the least susceptible would be something like Pomona Pectin. However, that pectin doesn't yield as bright and clear a preserve.

Honestly, people in the food industry have written dissertations on this issue. Sometimes with natural products you will have natural results, and this is one of them.

Too high an acid level is just one issue. Too high a sugar level can also be a factor as can the type or age of the pectin and the fill temperature in relation to the type of pectin used. Also, once filled, if the jar is shaken or sits too long on the shelf, breakdown will occur.

For the home preserver, sorting out these issues can be time-consuming and challenging. Obviously, the passion fruit is not responding the way the mint does.

If this is a favorite recipe and you really want to fine-tun the results, you'll have to monitor what you do and start tweaking one thing at a time on very small batches to see if anything will correct the problem. You might compare the recipe you're using with other passion fruit recipes. I'm sure there are many online, especially other country sites like Australia.

However, even then nothing is 100% foolproof because growing conditions and fruits will vary from season to season.

Carol

I know this thread is a couple of months old, but if you are at all interested in passionfruit jam, rather than jelly, I can share the recipe that I found recently...no pectin required. It is beautiful, and delicious!