If it weren’t for Philo T. Farnsworth, inventor of television, we’d still be eating frozen radio dinners.”

– Johnny Carson

Buenos Aires – Liquid nitrogen is cold. Really cold. To paraphrase Wikipedia: “It is a cryogenic fluid which is potentially capable of causing instant frostbite on contact with living tissue. When appropriately insulated from ambient heat, liquid nitrogen serves as a compact and readily transported source of nitrogen gas without pressurization. Further, its ability to maintain temperatures far below the freezing point of water – it boils at -196°C or -320°F – makes it extremely useful in a wide range of applications…” One of those applications, as I have now spent an evening watching, is creating oddball frozen dishes. Oh, and by the way, that admonition about instant frostbite? Very true – bite into one of these items before it’s “warmed up” to somewhere around the temperature of regular ice, and you’re just asking for tissue damage to your tongue and palate, or pick one up with your fingers… well, you get the drift. Here our instructors are pouring out some into a styrofoam container where it sort of steams away – amazingly enough, it’s cold enough that even though contact with air instantly vaporizes it, it chills the air around it enough to stay liquid for a good length of time – a two liter container, open to the air, seemed to take close to ten minutes until it was all vaporized – giving time to make things with it… as we shall see. Obviously this is sort of a “don’t try this at home” – I’d imagine most folk aren’t up for a huge canister of liquid nitrogen being delivered to their doortstep anyway.

I’m not even sure where to really start with this. Most of it was a little repetitive in terms of what was being done, just showing us a few different versions. One method, ladling liquid nitrogen into a liquid as you whisk it, is a fast way of creating a supercold sorbet of sorts – something that’s particularly useful if you want to create an alcohol based sorbet, we had a caipirinha demonstrated to us – it became a frozen one, not slushy, but really frozen, that got scooped into the – also frozen – shell of a lime. Another involved taking a liquid and putting it in a spherical spoon, semi-submerging it to create a frozen shell around a liquid center, and then coating that (or not I suppose) with something else which is then also frozen onto it. It results in, well, a frozen shell with a liquid or soft center – a couple of examples a little cream covered fruit juice, a raspberry and cream bonbon of sorts, or just a sort of semifreddo of pistachio, or even using a siphoned foam, and dropping dollops of foam into the liquid nitrogen to form a shell around the foam, as they did with a garlic and almond based cream. Two of the more interesting ones were a sort of “blini” of passionfruit topped with a little spoonful of a coffee and basil seed “caviar” – where the blini are made by putting liquid nitrogen under a sheet pan so that it gets extraordinarily cold, and then freezing scoops of a fruit pulp for a minute or so on each side; the other being probably the most interesting if most difficult to make, a soy sauce based liquid with agar agar or gelatin that is injected, using a large syringe, into some looped flexible tubing, then lightly chilled until the gelling sets, and then using the syringes again, filled with air, which pushes the gelled “spaghetti” out of the tubes – kind of fun to watch, and surprising that it works so effortlessly. Then the spaghetti are dropped into the liquid nitrogen to become crisp and topped with an air made from ponzu sauze. It was a little intense in flavor for most folk – essentially we’re just talking gelled soy sauce topped with ponzu sauce… and, I think universally we agreed that we liked both the flavor and texture of the noodles when they were just gelled rather than frozen – if they were topped with something more interesting and just served at ambient temperature, they’d probably be pretty fascinating – sort of a reversal on something like a zaru soba. I leave the rest of this class to a series of pictures, which you can probably figure out what they are from my description above: