Keeping mincemeat

Hi, please could you tell me how long the Christmas mincemeat lasts? I have regularly used it from the previous year with no problem, but last year after making some I came across some more unused that I had made in 2016. The 2 part-batches were being stored separately but unfortunately during the installation of our new kitchen this summer it has got combined so I have some that’s 1 year old and some that’s 2 and I don’t know which is which! Will 2 year old mincemeat be ok? How can I tell if it’s still good to eat? It is all in unopened jars.