A lot of people leave their ice cream in the fridge for way too long. Crystals form, it becomes foamy and just plain yucky. But most people scrape it off and eat it anyway.
But ice cream companies like Nestlé are looking to avalanche research technology to re-engineer ice cream.
The company's scientists are working with the Institute for Snow and Avalanche Research in Switzerland (SLF) to examine the microscopic ice crystals found in both snow and ice cream.
"Snow and ice cream both contain ice crystals, are both frozen materials and both materials that change over time," explains Dr. Hans Joerg Limbach, a scientist at the Nestlé Research centre in Switzerland. "The objective is to get a better understanding of ice cream and ultimately to produce an even better ice cream."
Their research relies on the only x-ray tomography machine in the world that allows long-term observation of tiny particles in a substance at temperatures of zero to minus 20°C.
Experts at the SLF monitor the evolution of ice crystals in snow and how this affects its properties -- key factors for understanding avalanche formation.
Ice crystals affect the properties of ice cream in a similar way, altering its texture and structure as they grow and change shape.
The collaboration aims to help Nestlé to solve a universal problem for all ice cream manufacturers: how to maintain the product's original texture and structure for longer.
Avalanche researchers found that the structure of snow is heavily linked to the risk of an avalanche. Ice crystals affect the properties of ice cream in a similar way, altering it's texture and structure as they grow and change shape.
"Ice cream is an inherently unstable substance," says Dr.Limbach, "As part of its natural ageing process, the ice will separate from the original ingredients such as cream and sugar.
"When you store ice cream in the freezer at home for a prolonged period, you will eventually see ice crystals begin to form in the product. This is water from the ice cream itself," he added.
"Any ice cream will change over time in the way that it’s described and this is the reason that we go into this research," he explains. "We want to make the process slower so we can make a better ice cream."
Across the ice cream industry, consumer feedback about boxed ice cream that is stored in the freezer often relates to its texture and appearance.
"We know temperature variations are not good for ice cream quality," Dr Limbach continued. "These variations can occur at different stages of the product's transportation and storage.
He explains that most home freezers are at a set temperature, but it's not consistent. "It fluctuates by a couple of degrees in either direction, which causes parts of the ice cream to melt and then freeze again. The ice cream can sometimes become chewy due to loss of water or air, or icier and harder to scoop."
The experts at Nestlé are working with an x-ray machine that allows them to record the size and shape of ice crystals and air bubbles in ice cream under home-freezer conditions. "It's very difficult to examine material at around minus 20 degrees," said Nestlé scientist Dr Cédric Dubois, who also works on the study.
"X-ray technology is normally used at room temperature, but this machine works within exactly the right range for frozen food," said Nestlé scientist Dr Cédric Dubois, who also works on the study.
"Previously, we could not look inside ice cream without destroying the sample in the process. This method is non-invasive and does not disturb the product."
The study found that as some ice crystals grow in size they fuse together, creating bigger crystals which cause the texture of the ice cream to coarsen.
"We already know the growth of ice crystals in ice cream is triggered by a number of different factors," added Dr Dubois. "If we can identify the main mechanism, we can find better ways to slow it down."
Nestlé's scientists' findings have recently been published online in the journal Soft Matter.
A follow-up study is now underway with SLF and a research group at the Paul Scherrer Institute in Switzerland. This will give the scientists access to technology that should enable them to examine even higher resolution images of the microscopic particles in ice cream.