[TED-Ed] Why is ketchup so hard to pour?

Ketchup: Favorite for some, while others, uh well...let's not go there! But, surely if you've had any kind of fast food, or have been with kids at some point in your life, you'd have had to pour out ketchup. But who'd have thought about this basic question: why is it so hard to pour?

You've squeezed, punched, pressed, shaken the container (from the bottle to the sachet), but probably never wondered to figure it out. Well, good for us - the smart people at TED Ed have tried to figure it out, and here's a cool lesson on understanding the why.


(Source: TED Ed)