ANDREA SEABROOK, host:
Speaking of parties, guess what? It's your birthday. Close your eyes, make a wish, and blow out the light bulbs? It's Science Out of the Box.
An electrified, edible birthday cake with LED lights instead of candles. It's just one of the concoctions dreamed up by Patrick Buckley and Lily Binns. They wrote "The Hungry Scientist Handbook: Electric Birthday Cakes, Edible Origami, and Other DIY Projects for Techies, Tinkerers, and Foodies." And they joined us this week at NPR Studios here in Washington. Patrick said there was one big stumbling block in crafting an electrical device to eat.
Mr. PATRICK BUCKLEY (Author, "Hungry Scientist Handbook: Electric Birthday Cakes, Edible Origami, and Other DIY Projects for Techies, Tinkerers, and Foodies"): It took a while to figure out what would make a good edible electronic wire, and we went through filtering gold out of Goldschlager and trying to lay traces of gold leaf on top of the frosting, which just wasn't quite robust enough. We tried all kinds of things - ElectroGel, you know, the kind of stuff for a heart test, and they stick pads on your body all over the place to measure electrical currents.
Ms. LILY BINNS (Author, " Hungry Scientist Handbook: Electric Birthday Cakes, Edible Origami, and Other DIY Projects for Techies, Tinkerers, and Foodies"): It's edible, but we don't recommend it.
Mr. BUCKLEY: Yeah, it tastes pretty horrible.
SEABROOK: You tried it?
Mr. BUCKLEY: I've tried it, yes.
Ms. BINNS: Patrick tried it.
Mr. BUCKLEY: I tried it, yes. All in the name of science, you know. Anything for science.
SEABROOK: And you ended up with this. Tell me what you're doing here in this - I should say to the listeners, you appear to have a string of licorice.
Ms. BINNS: I have a string of licorice, a special kind. It's called Pull-n-Peel, just by Twizzler. But it's particularly tacky. And when I pull apart an individual string and lay it on top of our preferred conductive material, which is varak, which is edible silver foil - it's used in traditional Indian cooking.
Mr. BUCKLEY: We found that this works fantastically to conduct electricity, and it's edible. So...
Mr. BINNS: In small amounts.
Mr. BUCKLEY: So you just simply - you simply just roll it up on to the licorice, and it kind of sticks. Just want to make sure there's an even coating. Because the electricity is getting conducted along the outside through this very thin layer of silver.
SEABROOK: It's like the opposite of a wire.
Mr. BUCKLEY: Right. And then you lay that across your cake.
SEABROOK: And you've attached the ends of these Twizzler - silver Twizzler lines to the watch battery.
Ms. BINNS: It's electrical tape.
SEABROOK: With - and just like in a little package of electrical tape, and then you just stick in the LEDs, and you make sure that both the contacts on the LEDs are touching...
Mr. BUCKLEY: Right.
SEABROOK: The two different wires.
Mr. BUCKLEY: And they light up.
SEABROOK: OK. So, this is really cute. But how do you blow out the candles if they're LEDs.
Mr. BUCKLEY: You don't blow out the candles. You have to snip the wires. It's like a ribbon cutting ceremony instead of, you know...
Mr. BUCKLEY: Plus. Yeah, right, snip. That's way better. You don't get saliva all over your cake. You don't have the hazard of fire.
SEABROOK: No wax. Wax.
Mr. BUCKLEY: No wax.
SEABROOK: Wax dripping on the cake.
Mr. BUCKLEY: Right.
Ms. BINNS: It's much safer than your traditional birthday cake.
SEABROOK: There seems to be a trend towards doing a little bit more science in your cooking. I've seen like shows on TV where top chefs are using vacuum pumps to get, you know, vodka into their cucumbers and, you know, weird stuff, weird science. Is that - is this more science, or is it more cooking?
Ms. BINNS: You're right. Everybody is in to doing science with food these days. People who've studied science are performing for an audience. And I would go so far as to say the same thing is happening in high-end restaurants, that molecular gastronomists are performing an incredible scientific and culinary act, and you're paying a high price for it.
What we're doing is all at home. It's open source. It's recycled material. It's scrappy, creative. Do it with your friends, figure out new solutions. So, this is totally a part of that.
SEABROOK: So, what's next? What is this? We're going towards alcohol here I see.
Ms. BINNS: It's a cocktail hour. We're going to make a martini with dry ice, which is negative 109.3 degrees Fahrenheit. So, you get a drink that is colder and less watered down. A martini - a normal martini famously has a half-life of five minutes, which is really just an excuse to slug it back. This one gets super chilled. It isn't watered down. Foams. Fizzes. Smokes.
SEABROOK: OK. I'm all for it.
Ms. BINNS: So, do you want to make this drink up?
Ms. BINNS: So...
SEABROOK: That is way too much Vermouth for most of my standards, but I will put...
Ms. BINNS: Just a drop.
SEABROOK: All right. I'm going to pour it into the shaker. Excellent. OK, in the shaker.
Ms. BINNS: Then you want to add your block of dry ice.
SEABROOK: You're going to use this whole block. It's about the size of maybe half a pack of cards, that thickness.
Ms. BINNS: Now. No Wait.
(Soundbite of poured block of dry ice)
SEABROOK: Oh, my gosh! It's foaming over. It looks like Halloween.
Mr. BUCKLEY: Steaming.
SEABROOK: Steaming out of the shaker. So, what do we - what is this? What's going on?
Mr. BUCKLEY: Science is happening here. Carbon dioxide in the dry ice is chilling your martini and is sublimating into a carbon dioxide gas.
SEABROOK: Sublimating meaning going straight from ice to gas.
Mr. BUCKLEY: Straight from solid to gas. And what you're seeing here is that cold is condensing the water in the air and creating a steam.
SEABROOK: Do you have to sit here and let it chill or?
Ms. BINNS: So, this is the case in which martini is better stirred than shaken. You don't want to seal containers with dry ice in them, and this completely seals it. And you don't want to shake it up too vigorously because then it can explode. The pressure can be too great.
Mr. BUCKLEY: Shall we pour it or do you want to pour it?
(Soundbite of poured dry ice)
Mr. BUCKLEY: This dry ice kind of resonates against the side of the metal container. You can hear that kind of hissing.
(Soundbite of laughter)
SEABROOK: I want to describe this martini. It looks fantastic. It's bubbling. The piece of dry ice you put in is bubbling, but their bubbles are filled with steam. So, they're kind of white, and they - when they pop at the top, they're offgassing. And it sounds very cool looking.
Mr. BUCKLEY: They actually look - make little smoke rings if you look closely.
Ms. BINNS: And they're kind of jumping off the surface.
SEABROOK: So, this is perfectly safe to drink?
(Soundbite of laughter)
Ms. BINNS: Remember, I told you, swallow the ice.
SEABROOK: Don't swallow the ice.
Mr. BUCKLEY: Just as safe as any other gin martini to drink. Let's put it that way.
SEABROOK: Cheers guys. Did you get into these martinis because it was just so cool? Or is it the usefulness, or is it the science? What are you doing here?
Mr. BUCKLEY: I mean, there's a real playfulness to everything that we do. We found that kind of food and techie culture has a lot in common, and that people like to take things apart and see how they work and put them back together in different ways. Your kitchen is kind of like your home laboratory. Why not have fun in it?
(Soundbite of bubbling)
SEABROOK: Thanks for coming by with this.
Ms. BINNS: Thanks, Andrea.
Mr. BUCKLEY: Thanks for having us.
SEABROOK: Patrick Buckley and Lily Binns are the authors of the "Hungry Scientist Handbook." You can find photos of the light up cake and a recipe for dry ice martinis. It's all on the website, npr.org.