But there’s more than meets the eye behind this ketchup quandary—it’s all down to science.

According to scientists on behalf of Heinz—the watery layer is due to physics. Ketchup is a colloid, which means it's a mixture of solid particles (like juicy tomato fibres) suspended in liquid (mainly water and vinegar). Over time, these solids settle, leaving a watery layer on top. The result? The dreaded watery squirt.

“Ketchup is a non-Newtonian fluid, meaning its consistency changes under stress,”explains Dr. Chris Clarke, Food Scientist and Physicist.“When left undisturbed, the particles separate. A good shake redistributes the solids and introduces kinetic energy, preventing that unwanted watery drizzle.”

For those who still forget to shake, we are launching a limited-edition bottle with a blurred keystone label—an artistic nudge to shake before use. Grab yours from Heinz to Home now. 

Available until the 29th October.