It seems the best thing to do is to have a sealed container with little air in it.
CO2 has proven to be useful, but its presence is not as important as sealing.
So, if you want to preserve cotton candy, my experimental results show that a sealed container is preferred. I obtained a conservation of 24 hours, but probably it will least 48h or even more.
EDIT: Well, sealing seems to work pretty well, but I have to report a pair of failure...
2 out 5 packages did not preserve the cotton candy for more than 24 hours, while the remaining did. On the plus side, the first experimental sealed package preserved cotton candy for more than a week.
Almost exactly what you describe can be done, it’s shown in this video.
The sugar isn’t hot blown, it’s isomalt, a lower-calorie sugar substitute used in lower calorie candies and by foodies because it is formable into interesting shapes, like your sphere. It's a sugar alcohol, derived from sugar, and is considered "natural" (see What does "natural" actually mean?).
In order to make your spheres by this method, you would need isomalt, wood chips, a smoking gun, a way to pump air, protective gloves, a heat source, scissors, a small cutting form and a fan. It will also probably require boatloads of practice. The video links to a kit with most of what you would need.
Don the gloves, warm the isomalt, and then knead the isomalt by stretching and folding, taking care to get it all to the same temperature. After it’s well kneaded, form it into a ball just bigger than a golf ball.
Poke the ball with a finger, creating a deep hole to wrap around the nozzle of your blower gizmo. Warm the hole and fit it over the nozzle of the blower gizmo. Now it’s a little like filling a balloon, but he shows a lot more finesse.
Once you’ve got the sphere blown, cool it with a fan.
Warm the scissors and cut the sphere from the blower.
He cuts a larger hole for filling the sphere with smoke, but I don’t see that that step is really necessary, if you’re smart with the scissors step. But, what do I know?
Fill the ball with smoke using the smoking gun.
Turn it hole side down onto a plate and serve immediately.
I'm sure with practice you could plug the hole for an even cooler presentation, but you'd still have to serve it pretty quickly.
You can flavor isomalt, and you can add interesting color designs. It seems like it could be a pretty fun project.
Best Answer
I assume you mean sherbet, which is made by mixing 1 cup of powdered sugar (also called icing or confectioner's sugar) with 1 tsp of baking soda (also called bicarbonate of soda) and 1 tsp of powdered citric acid. Altering the proportion of soda (alkali) to citric acid makes it more or less fizzy.