I was just wondering: Besides cost, how do manufacturers
end up with the beverage package of their final choice as either;
glass, plastic, or aluminum. For example, some milk is sold in
plastic while others are sold in paper boxes. With beverages, sports
drinks are mostly found in plastic (not aluminum), and then you have
beer that is only sold in aluminum and glass. Why is this?
There are tons of factors to consider, and ultimately every product has a unique
set of requirements and goals that lead to the type of packaging used. In many
cases, there is no ‘perfect’ package, so multiple options may exist.
1. Cost - You are right, cost is a big factor.
2. Use - How the container is to be used is another factor. For example, an athlete
might want to have a reclosable container, such as twist-top plastic instead of a
can or a carton.
3. Breakability - That same athlete might want a non-breakable container, whereas
a wine drinker might not be so concerned.
4. Gas permeability - A big factor that is more science-related is gas
permeability that means how much gas can migrate through the container. Glass and
aluminum are great for carbonated beverages because they block gas from moving in
or out. Before modern PTFE (a kind of plastic) bottles, carbonated beverages were
limited to glass and aluminum because the CO2 could leach out of PVC and PE (two
older types of plastic) bottles, leaving the beverage flat.
a. In wine, corks let in just a little air over a long period of time, helping
wines to age gracefully over years of storage, but corks are not supposed to let
water escape or enter (though they do sometimes, and now you see high quality wines
using synthetic corks or screw tops).
b. Screw caps for beer let in/out more gas too -- so lower quality beers might use
twist-off caps, but higher quality beers use standard tops.
c. Metalized plastic (such as are used inside boxed wines) reduces gas permeation,
blocks light, and eliminates the air space in the container more and more often,
high quality wines are being packages in boxes)
5. Light - Light penetration can affect beverage quality in milk, beer, and wine
(hence paper cartons, colored glass, metalized plastic, etc.).
6. Sterility Some drinks are prone to bacterial or fungal growth. Some drinks
are pasteurized (milk) or heat sterilized (juice, beer) to give them longer shelf
life. Aluminum containers are very easy to sterilize. Glass can be heated, but the
pressure buildup (gases expand when heated) can break glass. Plastics typically
are not compatible with high temperatures.
7. Chemistry for example, aluminum can be eaten away by acid for this reason
juices are typically packed in glass or plastic. Glass and plastics are typically
pretty chemically inert. Modern cans can be lined with a liner to protect the can,
or some juices can be made to be less acidic.
8. Flavor - Plastic containers also affect flavor strongly -- not only do flavors
leach out of the plastic, but some components of beverages will leach into plastic
as well (the oils that give orange juice its fresh flavor can bind tightly to
plastic). Drinks that are more delicate in flavor (like wines) would be less suited
to plastic containers than beverages where flavor is less important (soft drinks,
9. Temperature - a hot coffee or cold drink might be served in an insulating
10.Tradition/history - Tradition plays a huge role -- think of how the
characteristic shapes and glass colors of wine bottles tell you the kind of wine
11.Marketing - Marketing is always a factor
a. Color - many beverage makers want you to see their color (sports drinks again
come to mind -- color indicates flavor).
b. Shape - Many beverages use uniquely shaped bottles to identify them (coke
bottles come to mind, as does red stripe beer).
c. Brand information and/or nutritional data - any container must have some means
of labeling, and other containers have vivid art on them (wine/beer labels, orange
trees on juice containers, etc.).
12. Recyclability and other environmental friendliness considerations are also
Hope this helps,
The selection of packaging is a complex process that depends upon many,
often opposing, variables.
Shelf life, air permeability (especially oxygen), sensitivity to light,
storage temperature, reactivity the product and container, flavor changes --
it is a long list. An example is beer. Yes, it is sold in aluminum cans but
the beer does not come into contact with the aluminum because the inside of
the can and lid is sprayed with a coating of epoxy, and it is this coating
that actually comes into contact with the beer. Another very complex
packaging material is potato chips. There are up to six layers in a bag --
some functional, others decorative.
Packaging often costs much more than the product it contains.
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Update: June 2012