- Use a container that looks like a cauldron and is suitable for holding hot water
- Fill with 2/3 hot water
- When ready add a little dry ice at a time. Dry Ice pellets work great.
- When the water cools, refill with hot water (or reheat if possible)
Hint: A ‘soup kettle’ commonly found in restaurants and bars is really handy as the thermostat will keep the water hot, so all you have to do is add the dry ice for maintain the effect