When his three-year-old daughter refused to wear her jacket and asked how cold it really was, Warsaw photographer and filmmaker Pablo Zaluska, who works as ZALUSKArt, gave her an answer she could see: “It is so cold that even soap bubbles freeze.” At around −15 °C, he went outside, blew bubbles over the snow and filmed ice crystals spreading across their surfaces.
ZALUSKArt’s frozen soap bubbles in Warsaw
The session took place in Warsaw, Poland, and the resulting video, Freezing soap bubbles at −15 celsius — Warsaw, went up on 5 January 2016. Zaluska told Bored Panda that the shoot demanded real patience: only about 5 to 10 percent of the bubbles survived long enough to freeze, while the rest burst almost instantly.
The bubbles that did survive rest on the snow and slowly turn from clear, rainbow-tinted film into fragile spheres of ice. Feathery crystals start at one point, branch out like frost on a window and gradually cover the whole surface.
How soap bubbles freeze: the science
For years the swirling crystals were simply a beautiful winter trick. In 2019, a team led by Jonathan Boreyko at Virginia Tech explained them in a paper in Nature Communications titled “How soap bubbles freeze”.
- A bubble behaves very differently from a water droplet because it has almost no bulk liquid to carry heat.
- In uniformly cold air, at about −18 °C in the lab, freezing starts at the bottom where the bubble touches the cold surface.
- The freezing front releases latent heat, which creates a temperature difference along the film and drives a Marangoni flow, a current caused by changes in surface tension.
- That flow tears tiny ice particles loose and swirls them around the bubble while they grow, which the researchers named the “snow-globe effect”. The whole bubble can freeze in roughly ten seconds.
In warmer surrounding air with only a chilled surface, the freezing front creeps upward and stalls partway. The top can stay liquid for minutes until the bubble collapses, as air escapes through tiny pores in the ice.
Tips for photographing frozen bubbles
You need real cold. The soap solution used in the Virginia Tech study only froze below about −6.5 °C, so a still day well below freezing works best, and calm air keeps bubbles from drifting or bursting.
- Blow bubbles gently onto snow or a chilled surface so they can rest while they freeze.
- Expect most of them to pop. Like Zaluska, plan for many attempts.
- Shoot against a dark background, or with low side light, so the bright crystals stand out.
- Keep filming after the freeze. A collapsing shell makes a fine final frame.
For more on the physics, see our frozen-bubble film and science explanation. For tiny worlds made to last, explore Jenny Ayrton’s cast-glass worlds.
Related reading
- Chris Ratzlaff’s Frozen Soap Bubbles in Calgary
- Freezing Soap Bubbles: Patterns Forming on a Delicate Surface
- Angela Kelly’s Frozen Bubbles: Ice Crystals, Reflections and Fragile Forms
- Frozen Bubbles at Mount Washington Observatory
- Soap Bubbles in a Thompson, Manitoba Winter
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