How long will my pepper relish last, and how can I stretch it out?
I would dilute it with another sauce made the same way but with non-hot peppers if you want to make more of the same sauce you had last year. If you just want to use this up, two of my favourite sauces involve adding sriracha (which is pretty hot) to other sauces: added to mayo you can call it "sriracha aoli" as though you were on Top Chef, and it's yummy as a dipping sauce for meatballs, little pastry hors d'oeuvres and the like; added to plum sauce it is great in the places most people use plum sauce. I also put both sriracha and ketchup (but don't mix them) on hamburgers. So try mixing it into mayo, plum sauce, or ketchup, and see if you like what you've created.