I'm attempting to infuse alcohol for the first time, and I'm wondering how long the infusions will keep? I've read a few different (contradictory) opinions on this matter. One recipe for vanilla vodka said to store in the fridge and use within 3 months. I've even seen "use within a month" for some infusions. Others say, "it's alcohol, it will keep forever." I'd imagine the alcohol would act as a preservative allowing it to keep for a very long time.
In general, is there a reason to consume infused alcohol within a specific timeframe? Taste? Flavor? Safety? Would this differ based on whether it was infused with fruit, herbs, or spices? Is there a reason that you may want to store infused alcohol in the fridge/freezer instead of leaving it out?
Would there be any special considerations for what I'm infusing right now:
I use "one step" to sanitize bottles and caps, like you would do for beer, and bottle my infusions in that, and they've lasted >3 years. I've done raspberry and cherry vodka. If the alcohol percentage is high enough, it will kill bacteria or mold, so it's pretty safe for long term storage. Probably depends on the final alcohol percentage though, like if you add enough juice that the percentage goes less than 10 or so percent, you have to have more precautions in sanitizing everything. I usually sanitize anyway because it can't hurt, and I already have the equipment to do so from homebrewing.
My parents have been doing this for a while with Gin and an open bottle will last over a year without any detrimental effects. Generally with spirits you'll drink it well before it goes bad unless you're intentially aging them.
I will usually do a water-vinegar rinse to fruits or peels that I'm going to infuse into any alcoholic drink. I've made several bottles of vodka with fruit and raw sugar that have lasted over 5 yrs. Mostly because I can't drink and my family mostly doesn't but I like making them.