Five years to make a risotto: creating food for the Solar Impulse flight

Aeroplane food doesn’t have a reputation for being delicious, but we all know that creating tasty food on a big scale that lasts and is easy to reheat and serve is no mean feat.

It took eight scientists at the Nestlé Research Center (NRC) in Lausanne more than five years and 6000 hours to research and develop dishes for the pilots of the Solar Impulse plane, who are attempting to become the first to fly a solar-powered plane around the world.

So, what’s on the menu? Mushroom risotto, potato gratin and curry soup, among other dishes. These dishes were designed to survive extreme temperatures and varying climatic conditions, while being easy to consume and satisfying tight weight constraints - not to mention tasting good.

“There was a lot of trial and error involved. From testing new packaging to testing the food itself to see how it stood up to the conditions,” said Dr Amira Kassis, who led the research team. “Providing the required levels of nutritional quality is of the utmost importance to the pilots, and perfecting all of the various elements took time.”

The pilots will have two types of meals: a high-altitude version that contains high-energy, high-carbohydrate and fatty foods delivered in small portions and a lower-altitude version containing higher-protein foods in bigger portions.

After collating data on the pilots’ energy requirements, the team created a menu of 11 different meals and snacks tailor-made for each pilot. These were then tested via flight simulations in which factors like the pilots’ food intake, pre- and post-flight body weight and protein balance were measured.

The weight of every single morsel of food and drink needed to be taken into consideration, including the packaging, as the Solar Impulse is only as heavy as a family car. The total amount of food per flight could not exceed 2.4 kilograms and the volume of liquid could not exceed 3.5 litres (2.5 L of water and 1 L of sports drink).

Packaging was designed to minimise spillage, with pouches for soups and ‘flexi cups’ that turn into cups once opened. A specially designed self-heating bag is used to heat up some foods. The packaging was physically tested to ensure it could cope with air pressure fluctuations.

To preserve the food effectively, the Nestlé team developed a process whereby uncooked food ingredients are put into special packaging and then heat treated. This process seals in the freshness of the food and helps maintain its texture, preserving it for up to three months without the need for artificial preservatives.

The Solar Impulse departed from Abu Dhabi in March. Dr Kassis and her team are monitoring and managing the pilots’ diet and nutritional needs during the course of the plane’s five-month flight.

“We have been able to showcase our own technological innovation in the food we have designed and prepared for Solar Impulse,” Dr Kassis said.

“The years of research and the data we collect from the pilots during their flight will help advance our understanding of the ways food can be used to fuel this kind of endurance in the years ahead.”