How I did it:
Do at your own risk.
Be careful, containers and fruits can explode.
Be careful of extreme temperatures, both hot and cold.
Adiabatic cooling can create sub zero temperatures, freezing valves open and could cause frost damage.
This is a real party pleaser!
Do at your own risk! When I started this, I knew of nobody else doing this. There are now tutorials on the web.
This is what I did, and likely what you should not do.
1.) Find a pressure vessel, in my case an old pressure cooker in good working order.
2.) I modified the check valve spring. (It was a little week.)
3.) Cover venting valve with a cup so that it ejects water-vapor and air as it vents. This prevents valve from icing over and locking in the open or closed position.
4.) Lined container in reflective insulating bubble wrap.
5.) Created insulating outer covering for pressure container.
5.) Used dry-ice (CO2), up to 15 lbs.
6.) Allowed to sit for several minuets.
7.) Added insulating layers with holes, then fruit on top.
8.) Grapes, strawberries and watermelon (sliced work best)
9.) Whole water melons if left too long will freeze and potentially explode upon opening pressure vessel.
10.) added more insulation on top, but kept all valve areas clear, including the emergency pressure release.
11.) Sealed unit, and vented (unsprung) gas for 10 minuets to clear air out.
12.) Waited a minimum of 3 hours at 15 to 25 PSI. 25lbs psi seems optimal.
13.) Vent, open and enjoy fruit.
14.) Don't represurize. or store fruit- it goes to goo.
15.) Don't wait too long, as the fruit will freeze.
16.) Do at your own risk. Read how I did it… 20 months ago