Step 1 Materials
To make carbonated fruit you only need to gather a few things:
When making carbonated fruit it's best to use firm fruits, like oranges, apples and pears. I tried doing it with softer fruits like kiwis, strawberries and bananas and it just doesn't work as well. Apples in particular seem to work the best.
Bottle or Container
You will need a plastic bottle or a container to put the fruit into. I have found that a wide mouth Nalgene works best. You can use an empty 2 liter soda bottle however, just be careful not to add in too much dry ice, more on that later. DO NOT use a glass jar. The bottle will be under pressure and broken plastic is safer than broken glass. If you have a vessel that is designed to take pressure, like a beer keg for example, than by all means try using that.
The final thing you will need is a block of dry ice. You will only need a tiny tiny amount of dry ice to make the carbonated fruit, but its hard to buy less than a large block of the stuff. Now, chances are that you have never seen dry ice for sale. You can't make it on your own and you might not be able to find so easily.
I used the Dry Ice Directory to find out where it was being sold locally - they have listings for all over the world. I live in the east bay of California. I was surprised that In all of Oakland there was only one distributor - the AM PM Gas Station on Market and Grand in West Oakland. They oddly enough had a ton of the stuff for sale, and they are open 24/7! I was very impressed that I could buy dry ice anytime I wanted even if it was only for sale at that one place.
**Before you go to buy the dry ice please refer to this
Dry Ice Safety Info website. I am not going to go through all of the safety precautions that should be taken in this instructable, so take a minute to familiarize yourself with its possible safety hazards.**
*ps...I didn't copy the website info...if you don't know the dangers of dry ice look them up yourself*
step 2 Cut the fruit and put it into the bottles
The first step is to cut up the fruit and put it into the bottle(s). Cut the fruit as if you were making fruit salad - no seeds or orange peels are wanted here.
I cut smaller pieces to fit through the narrow neck of the soda bottle and bigger ones for the wide mouth of the nalgene. I highly recommend using a nalgene to make carbonated fruit.
step 3 Add the dry ice
The next step is to cut off a small chunk of dry ice from the block. You only need about 2 grams, or a piece about half the size of your thumb. There is no harm to putting in too little dry ice - you will simply end up with only slightly fizzy fruit. However, putting in too much dry ice IS dangerous and could make a really big mess.
Dry ice is constantly sublimating (not melting) from its solid form of CO2 to CO2 gas. Unlike regular ice made from water, it goes directly from its solid phase to its gaseous phase - no liquid phase in between. That is why it sublimates, rather than melts.
As a result, the dry ice block will produce gaseous CO2 until there is nothing left of the solid block. The bottles are going to be sealed tightly with their caps, so if too much CO2 gas is built up inside of the bottle they might explode (the soda bottle bursts at around 115 psi). We are looking for only a little bit of pressure (30 psi) and so there is no need to add in a big hunk of dry ice.
The dry ice in the picture below was enough for both of my bottles of fruit, so each one got about half of the small chips you see below.
step 4 Wait a day or two
As soon as I put the dry ice into the bottles and sealed the top I could see it turning into its gaseous phase. Most of the dry ice will sublimate in an hour, so thats all the time it will take for the bottles to become fully pressurized. Waiting overnight is a good idea to let the CO2 gas work its way into the fruit.
I put the bottles into an empty drawer and closed it for the first hour - I have to be honest, it was the first time I was doing this and I didn't know what would happen. After an hour I could see that the bottles were under pressure, but not in any danger of exploding, and so I transfered them to the refrigerator for the night.
You can only carbonate things that have water in them. I thought about doing fizzy meat, but I don't think there is enough water in it to dissolve the CO2 into.
I went to bed and brought the bottles with me to Instructables HQ the next morning.
step 5 Open, eat and burp
Once the bottles have sat overnight you are ready to open, eat and burp.
Bleed the pressure from the bottle buy opening the cap like you would open a soda bottle that had been shaken.
I cut the top of the plastic soda bottle off with a sharp knife and poured it out into a bowl. You can simply pour the fruit out of the nalgene bottle through the wide mouth of the bottle.
Now that the fruit is out of the bottles it's ready to eat! It loses its fizzyness pretty quickly, so make sure you chow down in the first 15 minutes after opening the bottles.
Carbonated fruit tastes like regular fruit, but it tingles on your tongue. It's a totally unique experience to eat, and makes you burp a whole lot if you have done it right.
I haven't done this yet but will post how it goes for me at my next dinner gathering. Adding fun to fruit is always a good time!
Cheers to the Instructables website...they've got some neat things going on.