Complex Numbers

Can We?

From The Takeout, answers to questions you never asked.

    Here's Why Canned Food Always Comes In A Ribbed Tin  

No, it's not "for her pleasure."

You might think the ribbed design on canned food is just a quirky touch meant to make jellied cranberry sauce look more interesting, but it actually serves a crucial purpose.

I might be alone in this, but I like the jellied cranberry sauce way more than the other canned kind, and way, way more than homemade. The uniformity of it appeals to me. I like to punch out both ends of the can and use one of them as a plunger, pushing out precisely 1/4" of the stuff at a time, then slicing it off at the can top. It's a far superior experience and taste.

Not that I'd ever tell that to someone who sweated over a hot stove to prepare homemade.

This is because the corrugated ridges add strength to the tin by creating a series of tiny arches along the surface. These in turn more evenly distribute pressure, similar to how the arches of a bridge help it carry heavy loads.

Always amusing to see someone unfamiliar with a subject (in this case, structural engineering) attempt to describe it to others.

Wait... is that how I sound all the time?

But the ridges have another job that goes beyond just strength.

Thus once again demonstrating the concept that things don't have to have just one purpose.

In addition to making the can stronger, the ridges on a can help it withstand heat. During the canning process, the contents are sealed and then brought to high temperatures to kill off any bacteria, helping to ensure that the food inside stays safe to eat.

In theory.

These ridges also help the can remain intact after it leaves the factory, when it might have to endure extreme temperatures during transport and storage.

I have a severe addiction to Coke Zero, and I buy it by the case. Obvously, Coke cans aren't ribbed, though their bottoms and tops are reinforced (because of how cylinders perform with pressure inside). Sometimes, on rare occasions, the reinforcement fails, and the bottom goes from concave to convex. On other occasions, it's the top that blows out, making it a whole lot harder to open the damn can. Unlike with canned food, this doesn't indicate that the contents have gone bad.

I suppose it's possible that some cans fail along the cylinder, too, and those are just culled before sale. But it seems to me that the sides of the can are not the failure points.

In the early 19th century, food was stored in glass jars that were heated to high temperatures to kill bacteria and then sealed to keep the contents safe.

Home "canners" still use glass jars. Duh.

The next big leap came in 1810 when English inventor Peter Durand developed tin-plated iron cans... Before the invention of the can opener nearly 50 years later, people had to use tools like hammers and chisels to access the food inside​.

Fifty years? Man, humanity really dropped the ball on that one. I guess they were too busy opening cans to develop a better way of opening cans.