I went to the store cupboard to fetch some pickles, and found Olive Oil all over the place.
One of my jars of Sun-Dried Tomatoes seems to have 'fermented', or 're-hydrated'. They probably weren't quite dried enough. Luckily my other jars are all OK.
I would have thought that being in oil they would have been safe, but as soon as I unscrewed the lid it started bubbling from the bottom, and the Tomatoes erupted; as you can see from the photo they were forcing themselves out through the top.
We learn by our mistakes, and I shall know next year to make sure they are very well dried; 4 days in the sun perhaps instead of 3.
I'm very annoyed with myself, as I'd considered them to be one of my 2017's success stories.
I did, of course, taste them; they were delicious.