Stainless Steel Flask

About 2 or 3 weeks ago, I made a mixture of brandy and pomegranate juice in a 1:1 ratio—though I don’t remember the exact proportions; one might have been slightly more than the other—in my stainless steel flask. My question is, I forgot to consume it and now I’m not sure if it’s safe. Since pomegranate juice already has an acidic/tart smell, I can’t tell if the scent has changed due to spoilage. How long do mixtures of spirits like whiskey or brandy combined with other ingredients last in these types of flasks, and are they safe to drink? (Since I made the mixture the flask stayed sealed)