When this pandemic started, it seems like everyone on the internet immediately began baking. We snapped up all the flour and yeast, and manufacturers and sellers are only just starting to catch up with our taste to stay home, nurture sourdough, and eat many delicious carbs.
I felt the impulse too but was briefly stymied by the shortages. So, I thought of an alternative sweet treat I could make that would be just as soothing, but wouldn’t use the elusive ingredients: Chocolates! And I found inspiration in internet security expert and culinary enthusiast Samy Kamkar. He has developed a home version of a process that makes a gorgeous iridescent coating on tempered chocolate — using nothing but the chocolate’s own reflective properties.
Kamkar made his futuristic chocolates by enlisting his home 3D printer to make a precise acrylic mould, and his engineering know-how to develop an even-pressure vacuum.
“To make the chocolate, Kamkar created a mushroom-shaped mold with multiple ridges micrometers apart. He tempered the chocolate, poured it into the mold and then put it in a vacuum chamber to prevent air bubbles on the surface. […]
As Renusha Indralingam explained in Yale Scientific in 2013, iridescence occurs ‘when an object’s physical structure causes light waves to combine with one another, a phenomenon known as interference.’ In the natural world, hummingbirds, beetles, butterflies, peacocks and many other living organisms exhibit iridescent traits, which they can use to choose and attract mates or evade predators.”
The pretty phenomenon results from forcing the chocolate into the diffraction grating (which is used in other, less delicious, applications like telescopes and X-rays). This allows the light rays that hit the moulded chocolate’s surface to scatter, making an iridescent rainbow sheen. The chocolate must be very cold in order to produce the interference — so the confection’s beauty is enhanced by the fact it quickly fades.
A Swiss manufacturer, ETF Zurich, has spearheaded industrial method to making this iridescent chocolate and is planning on scaling it up to general manufacture soon. I await their efforts: Even though I am so looking forward to witnessing this optical phenomenon in person, it still takes too many resources for me to do in my home kitchen!