I bought a pineapple about five weeks ago, and left it out in the window box above the kitchen sink for nearly three weeks. Fred cut it up for me one morning, and it was obvious at the time that it fermented because it had a strong taste of alcohol. At the time, I said I was going to head out that day and get a fresh pineapple to repeat the process for pineapple vodka.
Tighten the lid well or you'll have the CO2 gas escaping, which you don't want to have happen at this time. You want it to gas (means it's fermenting), but you MUST crack the jars open every day in the beginning to allow the gas to escape. If you don't, the lids will buckle and the jar will burst...and all your vodka will go all over the place, and you're out time and cash. Once the fermentation is going hot and heavy (lots of bubbles in the jar), I move it from a warm location to the fridge to slow the fermentation down; don't worry, it doesn't stop fermenting in a cold environment. Once you move the jars into the fridge, "burp" the jars every other day for the first two weeks, then you can start backing off to every two days. You have to keep an eye on the lid - if it's bowed and it's before the "burp", go ahead and crack it open and release the gas.
You want to seal the jars back up tight because you don't want to expose it to air very long or it'll taste like vinegar. Oh, and it DOES matter what kind of jar you use; mason jars with lids will allow you a much tighter seal to hold in the gas. Now you might think it's ok to use a plastic bottle or an old salsa jar; your vodka will taste like vinegar if you do because they're not airtight containers.
And here's the bottled product! Typically I leave my brews out in a sunny locale so it gets warm and helps get the fermentation process started. I figure it doesn't
really matter too much about the quality of the vodka at this stage as in a year it'll have a great
pineapple taste (and when I get back to work in a few days, I'll buy some good stuff and put it away for year when I do this again).
Yes, I let my brews age a solid year, but you don't have to. Why go through the trouble of aging your mixture? Well, if you do, then the alcohol has time to develop flavor and character; it's akin to a really good sipping alcohol you want to savor, not slam back shots with. You really begin to cherish it as "the good stuff"!
If you chose to ignore my suggestion about the jars and used whatever kind of container you had on hand, skip the fermenting process and just toss it in a dark cabinet and shake it once a day over a 4-6 week time frame. Pull out the fruit, drain, strain the mix through a coffee filter, and bottle. Make sure you test your jars first for water leaks as some seals really stink, and you don't want a pineapple vodka "shower" while you're shaking the mixture.
I never started out to make "homemade hooch"; my goal was to brew extracts for my baking. To me, I was tired of paying $3-$7 for a bottle of flavoring, and I thought about how vanilla extract was made, so I guessed it'd be the same process with other fruits. It's not always true, and I suspect my original failures were due to not using mason jars (I ran out of them at the time, and didn't have any clue what I know now), and using frozen, not fresh fruit. Yes, that does make a big difference from my own experiences...why, I have no idea.
Happy Eats! :)