URGENT - baking powder overdue

[ss_storm]

yeah they will still be fine to eat, they just might be a bit flat! much like self-raising flour, it tends to become 'inactive' after a period of time. there is a way to test if it is still working ok, put some in some liquid (cant remember what you put it in!) and if it fizzes it's still good, but if there's nothing it's time to get some new stuff

[CrazyLady]

I think if you put it in vinegar but not 100% sure.