I have a question about the recipe "Jeffrey Morgenthaler's DIY Grenadine" from Genius Recipes. How long will the grenadine last if adding ounce of vodka?
Sounds like you want to store this for more than a month. Recipe suggests, for longer but unspecified keeping, either adding an ounce of vodka to the whole recipe or freezing it.
My guess for the new fridge duration is somewhere between 4 mo and a year, with you checking at intervals and discarding if mold develops.
Maybe longer for freezer storage.
But/and if you think the recipe gives you too much to use conveniently, it would be easy to make half, then make again when you need more.