7

Dry ice ice cream

TUTORIAL

Above

An ordinary food

processor will crush

dry ice pellets to a

fine powder

Below

Decant your ice cream into Tupperware and leave

it in the freezer to fully discharge any leftover dry ice

SAFETY

Minus 80°C is cold. It’s easily possible to hurt

yourself with this, so don’t touch it with bare skin

• wear a solid pair of insulating gloves (regardless
  of whether or not you’ve seen people on YouTube
  handle it bare-handed). We used a pair of welding
  gauntlets, but any solid and dry pair of gloves should
  work. Even with these, it’s best to avoid touching the
  dry ice as much as possible. Move it with a scoop,
  rather than by picking it up by hand.
  As dry ice warms up, it sublimates directly into
  gas. At room pressure, you won’t get a liquid. This
  gas is odourless and invisible. If the levels of CO 2
  build up in the air, it can cause problems with your
  body’s ability to expel CO 2 from the blood, and
  this is dangerous. Make sure you do this in a very
  well-ventilated environment. Ideally, store the CO 2
  outside, and only bring in small quantities as you
  work with them. Even with this precaution, all efforts
  should be made to improve ventilation and you
  should ensure that a good fresh air supply gets into
  the room you’re working in. Be particularly cautious
  of this if you have to transport the dry ice by car.
  CO 2 is heavier than air, so will sink in the room.
  As such, children, pets, and other creatures that
  breathe closer to the floor are at a higher risk than
  tall adults. It’s best to keep them out of the area
  when working with dry ice.
  As dry ice sublimates, its gas takes up a much
  larger volume than the solid form did. If you put it in
  a sealed container, it will increase in pressure until
  either all the dry ice has sublimated, or the container
  explodes. As such, always store your dry ice in a
  container with a loose-fitting lid to let the gas out.

We found that, when making ice cream by hand,

whipped cream-based recipes worked best.

Start with all your ingredients chilled in a fridge (see

recipes on page 104 for what you need). Starting with

everything cold will mean that it will freeze faster.

Then whip the cream until there are soft peaks. This

will trap air inside and the bubbles will also help limit

the size the ice crystals are able to get to. The next

step is to add all the other ingredients (except the

dry ice) and mix them in. You want to ensure that

everything is thoroughly mixed, but with a gentle

stirring action, rather than the more vigorous whisking

you used earlier.

Now it’s time to add the dry ice. Before the dry

ice gets into the mixture, though, you need to make

sure that it’s well ground down, to a fine powder.

This will help chill the liquid evenly and ensure that

the dry ice sublimates quickly (rather than creating

super-cooled blocks frozen around a chunk of dry

ice). This is easily done using a food processor. Take

a small amount (around a medium-sized mug-full) of

dry ice pellets, put them in your food processor, and

mix until you’re left with a fine powder. Be careful

when doing this because you don’t want little bits of

dry ice flying around, and at this point the dry ice will

start to sublimate quickly – see the safety box left

for details.

Add this powder to your liquid dessert a spoonful

at a time. Be careful, as any dry ice spilling out could

get on you. Wear gloves and other protective clothing

to make sure it doesn’t get on your skin. Sprinkle it