Some scientists struggle to observe the most distant stars, while others have spent decades calculating the probability that habitable planets exist elsewhere in our galaxy. For a pair of Greek researchers, there was a more pressing problem: is it possible to cook chips in space? The team, from the Aristotle University of Thessaloniki, have confirmed that chips can be fried — quicker and crunchier, in fact — at three times the normal gravitational force, in conditions equivalent to those on Jupiter.
However, achieving a pleasingly crispy exterior may be more challenging in the reduced gravity conditions on Mars or the Moon, they predict. Thodoris Karapantsios, a chemical engineer who led the study funded by the European Space Agency, devised a hyper-gravity simulator for chips by building a rotating industrial fryer capable of producing centrifugal forces equivalent to nine times the Earth’s gravity. In normal conditions, bubbles form in the potato as it fries, which move to the surface because of gravitational forces once they reach a critical size. This process happens more quickly in high-gravity conditions, improving the rate that heat is transferred from the oil to the potato.
In 3g conditions the potato fried twice as quickly as usual and its crust reached its maximum thickness. Any further increase in gravity levels did not improve the chip’s crispness, the researchers found, leading to the conclusion that Jupiter is probably the most efficient place in the solar system to make chips (aside from the fuel required to get there).
Their paper, The Effect of Increased Gravitational Acceleration in Potato Deep-Fat Frying, is in this month’s issue of Food Research International.
In a taste experiment, student volunteers were unable to tell the difference between normal and the hyper-gravity chips, although Professor Karapantsios conceded that this did not constitute a “professional” taste test.
The team are submitting a patent proposal for the high-gravity chip fryer, which they believe will be of interest to fast-food outlets.
The next step will be to rerun the experiment in low-gravity conditions on a parabolic flight, also known as the “vomit comet”.
Professor Karapantsios predicts that the chips are likely to be unpleasantly soggy. In zero gravity there is no force causing the air bubbles to detach from the chip.
“The result is probably more like boiled potatoes than fries,” he said.
This means that if astronauts on the International Space Station wanted “regular” fries, they would need to take the hyper-gravity centrifugal fryer with them.
Space menus have improved substantially since the days of freeze-dried ice-cream, but many astronauts say they miss the comfort of home-cooking.
For Thanksgiving last year, the six crew members aboard the International Space Station had a holiday dinner that included freeze-dried green beans, thermostabilised yams and slices of turkey warmed in a hermetically sealed pouch.
Chips are now, theoretically, possible but it may be some years before they appear on the menu. “Frying a container of oil at 180C in a spaceship is a safety concern,” said Professor Karapantsios.