I bought and prepared some food a few days prior to buying the dry ice.

• Strawberries,
• Raspberries,
• Mangoes,
• Kiwi fruit, and
• Rainbow ice cream.

I separated each foodstuff and froze them in our regular -18°C freezer. I cut the ice cream into slabs approximately 15-20mm thick. I cut the mango and kiwi fruit slightly thinner for no good reason. I left the berries whole. At this point I noticed I'd accidentally bought low-fat ice cream. I think this will give a better, crunchier result, but I generally loathe low-fat foods.

I also filled some PET bottles with methylated spirits and put them in the freezer to give the cold trap a running start. I didn't want to use up lots of dry ice “coolth” by bringing the metho down to -70°C from room temperature.

I took the boys with me to IcePac in Woolloongabba. They were slightly more expensive than another nearby supplier but they had their prices on their website which I want to support. I bought a 10kg brick for AUD$58, plus a bag of normal water ice for general purpose chilling.

I set up the ethanol and dry ice bath, double-bagged the ice cream, and floated the ice cream on the bath. The food ideally should be at -35°C at the start of the process, but I couldn't see harm in it being too cold. I figure it might just take longer to get started.

Breaking the dry ice brick into bits was harder than I expected. I hit it with a welding hammer and was rewarded with a shower of dry ice flakes all over me. Fortunately I was wearing my safety glasses and the kids were at a safe distance. I found a hammer and chisel worked well, producing large chunks that were easy to handle.

I pre-chilled the cold trap jar and food pot prior to setting everything up.

The bath coming down to temperature.

Once the ice cream had been in the cold bath for half an hour or so I turned it out into the chilled stainless pot. I put the cold trap jar into the cold bath and it instantly cracked right around the bottom.

Beans.

I put my spare jar (two is one, one is none) into the big esky with the dry ice, along with the stainless pot and ice cream, to pre-chill. After another half an hour or so I set everything up again, turned on the vacuum and everything held.

After an hour the ice cream had started to melt a little as the pot absorbed heat from the environment. I put the pot into another esky and filled it with the water ice to slow that process down. There was some condensation on the outside of the cold trap esky so I put a sheet of insulation foam underneath it to slow down conduction from the tabletop. Once the pot goes onto the hotplate I will put the cold trap into the bigger esky to insulate it further.