Why cans of soup are shaped the way they are

My grandpa designed the bottom of modern beverage cans. The reason for that shape is two-fold. First, the bulge is for pressure resistance. Second, the rest of the design was created specifically for the optimal application of the epoxy spray that prevents your drink from developing a metallic taste. Unfortunately, he didn't patent his work and Anheuser Busch ultimately took his idea for themselves. Never prevented them from being his client though, for other seamless can tooling work.

The &quot;So why not for everyone?&quot; section is interesting, but misses the reason the tuna can is actually the worst shape on the list: it&#x27;s optimized for surface area of the top and bottom of the can! Tuna is actually cooked in the can (retort cooking) and the high surface area is beneficial to this process.<p>Maybe not the most <i>useful</i> thing I learned in Calc 1, but the thing I remember best.

I feel like there are other efficiencies not considered in the article. Namely spoilage and portion size. I mean, you&#x27;re not usually gonna need a bunch of tuna at once, so you don&#x27;t want to have a huge can full of enough tuna for twenty people - but you also need it to be in a can big enough to manipulate. Also one with a big enough visible label space to actually put something legible on it.

The article asserts:<p><i>&quot;Aesthetically, a slightly taller can looks nicer. The Golden ratio is approx 1.6, so a can with a height of approx 1.6x it&#x27;s diameter (3.2x the radius) would be very appealing.&quot;</i><p>However, it is a myth that the Golden Ratio is the most appealing ratio. Many things, from the Parthenon to paper sizes, don&#x27;t have a golden ratio and that doesn&#x27;t make them less attractive[1].<p>Also, the supermarket in my neighbourhood sells soup in a variety of containers (cans, tetrabriks, plastic bags) and if only the standard soup can would sell well, I wouldn&#x27;t see the other packages.<p>[1] <a href="http://skeptoid.com/episodes/4325" rel="nofollow">http:&#x2F;&#x2F;skeptoid.com&#x2F;episodes&#x2F;4325</a><p><i>&quot;Perhaps the best known pseudoscientific claim about the golden ratio is that the Greek Parthenon, the famous columned temple atop the Acropolis in Athens, is designed around this ratio. Many are the amateurs who have superimposed golden rectangles all over images of the Parthenon, claiming to have found a match. But if you&#x27;ve ever studied such images, you&#x27;ve seen that it never quite fits, at least not any better than any other rectangle you might try. That&#x27;s because there&#x27;s no credible historical or documentary evidence that the Parthenon&#x27;s designers, who worked more than a century before Euclid was even born, ever used the golden ratio in any way, or even knew of its existence.&quot;</i>

Cans of soup are definitely not spherical for space-efficiency. They&#x27;re spherical because from the assembly line to shipping to the customer, they simply work better. They handle dents well, they roll along assembly lines fluidly, they keep the orientation of the product labels, they&#x27;re easy to inspect for quality, and they pack and unpack well. Obviously they also stay put on a shelf...<p>In terms of dimensions there&#x27;s several factors to consider: label size, stacking efficiency and directional integrity. If you want a nice big color photo of your product, a taller, slimmer container will allow for a large color background and plenty of text for both the front and rear labels. Depending on if it&#x27;s skinny or wide will determine how other products can be stacked around or on top&#x2F;below it. And some foods (like tuna) keep their shape&#x2F;consistency better when laid horizontally to prevent from breaking up while being transported. Similar foods hold together better when the pieces are larger, so larger portions of canned fish have the typical vertical orientation. And of course there&#x27;s only so much horizontal space that can be allocated per unit before the shelves burst at the seams.<p>For sealable cuboid containers, more and more containers are being modified with grippable edges to make it easier to handle, since the customer doesn&#x27;t use the entirety of the product at once (<a href="http://ecx.images-amazon.com/images/I/81W3JCB8tHL._SL1500_.jpg" rel="nofollow">http:&#x2F;&#x2F;ecx.images-amazon.com&#x2F;images&#x2F;I&#x2F;81W3JCB8tHL._SL1500_.j...</a>). Resealable bagged containers are also becoming more popular, as they reduce the amount of air in the container, pack more efficiently, save weight, and are easier recycled. (<a href="http://www.gofoodindustry.com/uploads/members/comp-1509/files/TROOTS-BLENDS-IN-RESEALABLE-BAGS---1308818370-DJW24678.jpg" rel="nofollow">http:&#x2F;&#x2F;www.gofoodindustry.com&#x2F;uploads&#x2F;members&#x2F;comp-1509&#x2F;file...</a>)

&gt; If we wanted to use a shape that packed perfectly efficiently, we’d use some kind of cuboid... But we don’t see many cubes on shelves. Let&#x27;s look at cylinders now...<p>The only real reason the article gives against using cuboids is that &quot;the edges would be stress points&quot;, but it goes on to imply that this is mostly solved with &quot;filleted (rounded) edges to reduce stress concentrations and to make them easier to manufacture.&quot;<p>I enjoyed the rest of the article relating to the optimal dimensions of the cylinder, but I still don&#x27;t really understand why more products don&#x27;t use cuboids (with or without filleted edges). Surely the space savings for shipping and shelving would be pretty significant, no?

The article fails to mention the main reason food is shaped &quot;inefficiently&quot;: serving size.<p>Besides being cooked in the can (as egypturnash points out), a can of tuna contains two sandwiches of tuna. A jar of tomato sauce contains two servings of tomato sauce. A can of soup contains two servings of soup.<p>Yes, you have to be able to hold it in your hand, and stack it on a shelf. But you can&#x27;t make a smaller can because that would be &quot;less soup&quot;. No one wants to buy smaller cans of soup, and the manufacturers certainly don&#x27;t want to sell less soup per purchase either.<p>Economics trumps material efficiency.

We do have a lot of cubes. Juice boxes. Cereal boxes. Wine boxes. Cylinders are pretty much only used when you need to fake larger capacity for consumer preference (cardboard nut containers in super markets vs. plastic cubes of them at Costco) or you need to use metal for some reason (e.g. tanks of pressurized gas, holding liquids with the top off, etc.). I think he kind of misses the point that cubes are superior in terms of space usage then goes and analyzes how space efficient something we are only forced to use for other reasons is.

This leaves out or glosses over some very important areas, namely the use to which the can is being put. Soup cans are taller than ideal for minimum material use in part because it&#x27;s <i>easier</i> to pour from them, while on the other hand a tall skinny tuna can would be hated. For a more extreme example, consider the guava paste can - an inch high and 6-7 inches across because of how the product inside is used. Think about trying to pour your soup out of <i>that</i>.

I think the authors overlooked the most obvious reason for cans being cylindrical: a cylinder is very resistant to vertical compression, so you can stack cans very high on pallets without worrying about bottom layer deformation.

&gt; The purpose of a food can is to store food.<p>Absolutely not. The purpose is to maximize profit.<p>The can improves profit via sales (being appealing on the shelf and in the kitchen cabinet; perhaps a familiar shape sells better), marketing (the image of the brand and the product, including environmental issues), distribution (the obvious costs and the value of being appealing to the sales channel (e.g., oversized products might be unappealing to the supermarket)), manufacturing costs, functionality for the consumer (food stays fresh, fits standard can-openers, etc.) etc etc.

On a related point - I just finished reading &quot;Atomic Accidents: A History of Nuclear Meltdowns and Disasters&quot; and the author specifically mentions how the &quot;can of soup&quot; shape is pretty dreadful for holding fissile materials:<p><a href="http://www.amazon.com/Atomic-Accidents-Meltdowns-Disasters-Mountains/dp/1605984922" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;Atomic-Accidents-Meltdowns-Disasters-M...</a>

My first day of calculus in high school, Mr Haskell told us that in a few months we would be able to prove the ideal size for a soup can. And we did!

How about the cost of the food? Tuna is expensive, condensed milk is cheap. That matters relative to the cost of the can because it&#x27;s more important to make the condensed milk can cheap to store a cheap ingredient, than to worry about the minor cost of aluminium compared to expensive ingredients like tuna.

No mention of can openers, and how they work their way around the cylindrically shaped can?<p>Think of how a can opener would work with a cube, hexagonal, or other shaped can.<p>Cool article, but seems it builds a lot of assumptions into its analysis.

Cans of soup could also be shaped the way they are due to the fact that it might be easier to pasteurize a cylindrical can than a cube. The heat can be more evenly applied to a cylinder than a cube.

There are lots of other really good articles on that blog: <a href="http://www.datagenetics.com/blog.html" rel="nofollow">http:&#x2F;&#x2F;www.datagenetics.com&#x2F;blog.html</a>

The M&amp;M shape is the most efficient for minimizing empty space in shipping containers. They missed that one.

they need to start optimizing the shape of nacho cheese jars so that i stop getting rim cheese all over my knuckles every time i dip a chip

Great post, but &quot;data genetics&quot;? It would be nice if they didn&#x27;t misuse the word genetics — this site has nothing to do with genetics.

Thanks, I also liked reading the last article about ice cream.<p>Your articles remind me how much calculus&#x2F;math I have forgotten since leaving school and, sadly, how little use there is everyday to use calculus :(