Although deception cannot be ruled out, the more likely reason is automation.
Very few companies can their own beverages. Rather they contract out to local bottling (canning as well) companies. The home office sends the concentrate, called syrup, and local bottlers combine the syrup with local water and squirt it into bottles.
This process is particularly efficient since only the syrup needs to be transported over great distances.
Each bottler doesn't have every possible kind of bottling equipment. The bottler probably can only handle a few different kinds of cans and bottles. Small market items probably don't sell enough to warrant retooling of the machines, so they have to share equipment and thereby cans.
Why are coffee and tea cans differently shaped than soda cans? Marketing mostly. A different can helps them to stand out from the run of the mill soft drinks.
Zeke Kossover
...who had a classmate in high school whose parents owned the local bottling company.
----- Original Message ----
From: Anthony Lapinski <Anthony_Lapinski@pds.org>
To: tap-l@lists.ncsu.edu; tap-l@lists.ncsu.edu; phys-l@carnot.physics.buffalo.edu
Sent: Wednesday, September 5, 2007 1:59:07 PM
Subject: [Phys-l] cans
I found two empty aluminum cans this morning at school: Enviga (Nestea)
and Iced Coffee (Starbucks). These cans are thinner than the normal 12-oz
varieties. What surprised me was the labels. Enviga said 12 oz (355 mL)
while Iced Coffee said 11 oz. (325 mL).
I asked my students about this. One said Enviga was carbonated and that
maybe the volume of fluid went down after you opened the top. Another said
that the coffee was foamy, and maybe this had something to do with it.
Nobody really had any good ideas.
So if the labels state how much fluid is actually in the can, why not use
different size cans? Or is there some type of deception here?