I bit into the nectarine and almost spit it back out because it registered as rotten, even though I'd bought it not 4 hours before and it was superfresh then. I tried the grapes and got the same input, but not the same reading on it. It turned out that the cooler held in enough gas to carbonate the fruit as the dry ice sublimated. I just couldn't make myself finish the nectarine, even though I tried, because it really gave the sensation of eating food that had started to decompose. But the grapes? Fabulous fun. I don't know if everyone would have the same reaction - I had previously bitten into bad peaches but my reactions to fermented grapes remains entirely positive to date.
Recently, I learned that high altitudes can kill the ability to sense carbonation, as can some anti-altitude-sickness meds (and likely other things as well), which means that we have carbonation sensors in our tongues that are separate from other things. I think that's pretty cool. And I think of carbonation as another thing we can taste since it registers partly between sensation (hot/cold/wet/dry) and flavor. It makes sense that some people don't like carbonation given my inability to finish a perfectly good carbonated nectarine due to the association with rot. Fortunately, I have more positive interactions with carbonation.
Ever since then, I've wanted to try carbonating grapes again to see if I could get it to work. Last night, while picking up some supplies (for key lime cake) I noticed a cooler of dry ice at the supermarket for $1.49/lb and bought about a pound of it. I tried 3 different containers.
- Initially, I wrapped the dry ice in some paper towels, put it under a makeshift shelf, put grapes on top and wrapped it in 3 layers of supermarket plastic bags and stuck it in the fridge on a towel to keep the glass shelf from shocking. About 4 hours later, there was a smidge of carbonation.
- Figuring that a pressure vessel with a relief valve would be better, I stuck them in my pressure cooker. But it never built up enough pressure to seal well, so the results were kind of paltry there too.
- Lastly, I just stuck the remaining hunk of paper towel wrapped dry ice with the grapes in a gallon ziplock and stuffed it back in the fridge figuring that if it did explode from pressure, it wouldn't do much damage. And if the grapes froze instead? I like frozen grapes too.
UPDATE: If you try this, and want to share, don't do it more than a day in advance, and try not to freeze the grapes. The frozen grapes are good frozen, but not if they thaw out, and the CO2 seems to encourage browning as well (seeing as it feeds plant life, that makes sense). I did vinegar rinse (swish in 1part vinegar/3 parts water, rinse, dry) all my grapes before carbonating to be on the safe side and they're still looking a little miserable two days in. Some still look ok and they are still carbonated but the bag is no longer puffed up.
SAFEY UPDATE: If it wasn't perfectly clear - don't confine dry ice in anything that won't leak at least some, or pop open harmlessly at a low-ish pressure. Soda bottles? Right out. They will blow up into bits of shrapnel. Fun outside, not so much in your fridge or your face. Stick to flexible things or unsecured lids. See comments for technical details if "don't" is insufficient for your rebellious nature.