The primary concern with spices pH is when dealing with low-acid foods. Since most all fruit jams are acidic pH I don't think it is an issue. Others will correct me if I'm wrong.

Most all vanilla beans I have any access to are dried already. But even if you have a fresh bean the pH shouldn't be affected all that much given the acidic nature of the fruit. There are a couple of exceptions - figs is one off the top of my head - that are low-acid fruits.

Dave

Vanilla beans are dried orchid pods. Obviously the moist beans still have plenty of residual oils, but of all the things I might worry about with preserves, that would rank at the bottom.

I would not be at all concerned about using vanilla in any preserve, even something like fig (which usually calls for lemon juice to bring down the pH). Generally, the preserves are cooked with the bean and once the preserves are infused, the bean is removed. So if there were any potential risk (purely hypothetically), removing the pod would take care of the problem.

Carol