By Jeffrey Zurek
It is summer, it is hot and it is probably smoky.
Instead of another column highlighting climate science, let us dip into some summer nostalgia because nothing hits the spot quite like a cold scoop of ice cream.
But while we treat it as a simple, nostalgic comfort, behind every frosty serving is a masterclass in multi-phase physics, chemistry and modern engineering.
Ice cream is far more complex than its basic ingredients suggest.
Far from being a uniform frozen solid, a commercial scoop is actually a delicate architectural balance of three distinct phases existing simultaneously: an unfrozen serum phase of liquid water holding salts, lactose and proteins; a branching network of millions of microscopic, partially coalesced fat globules and ice crystals; and injected air cells known as overrun that keep the dessert light rather than dense.
This intricate structure is whipped together inside industrial scraped-surface freezers, where rotating blades constantly shear the mixture to keep ice crystals microscopic while forcing fat globules to build their structural backbone.
The modern supply chain brings its own challenges with products needing to travel to the supermarket, and yet store-bought pints survive months in a freezer while homemade batches quickly turn grainy. Home freezers naturally undergo temperature cycles. When they warm slightly, smaller ice crystals melt and their water molecules migrate via diffusion to feed larger crystals, ruining the texture. To prevent this, formulators add natural gums like guar gum, xanthan gum or carrageenan. These long-chain molecules act as an essential insurance plan, binding free water and increasing viscosity to preserve a smooth mouthfeel through every step of shipping and storage.
That structure and those ingredients are also the secret behind those viral summer news stories asking why an ice cream sandwich left out in the sun refuses to pool into a puddle. The ice cream does indeed melt, but it fails to collapse because it is held together by its robust fat network and added ingredients that thicken with water.
The same underlying principles explain the distinct divide between soft serve and hard-packed varieties. Soft serve relies on specific sugar ratios to lower the freezing point, paired with a warmer dispensing temperature that keeps it flowing smoothly through a nozzle, a mechanism that also restricts solid inclusions like cookie dough.
Whether you opt for a budget tub or a dense, premium formulation, science has given us superior ice cream that defies the elements and stays delicious all season long. The next time you grab a spoon on a hot summer afternoon, take a moment to appreciate the microscopic fat networks and crystal-control chemistry working behind the scenes.
Jeffrey Zurek is a PhD from SFU, a P.Geo. and the host and producer of Whimsical Wavelengths, a Burnaby-based science podcast. Whimsical Wavelengths won the American Writing Awards as the 2026 Podcast of the Year winner in the science category.
Featured image: Zach Camp/Unsplash