00:00People have strong opinions about soda containers.
00:03Cans are significantly better than bottles.
00:05I think bottle probably tastes the best to me.
00:08A can keeps it colder.
00:10I prefer a glass bottle of soda.
00:12But does the container really affect the flavor?
00:15Soda companies claim to use the same proportion of ingredients.
00:18A company spokesperson for Coca-Cola told us that Coca-Cola uses the same recipe, regardless
00:24of the package type, and that it's best enjoyed ice cold.
00:28But there are a few factors that could still affect the way you taste it.
00:32First, let's take a look at the ingredients in the containers.
00:36Glass bottles are pretty basic, and contain no other chemical ingredients besides the glass.
00:41So there's nothing in it that could really change the taste.
00:46Cans are typically aluminum, lined on the inside with a polymer that can contain BPA, or bisphenol
00:53A.
00:54Rick Sockleben, a retired chemist with the American Chemical Society, says this has little
00:59effect on the taste.
01:00The amount of that material that would get into the contents of a container are so low,
01:05I don't think it would have any effect on flavor.
01:07This lining protects the taste of the soda, and keeps it from being contaminated by the
01:12metal.
01:12So the likelihood of having a break in that lacquer coating, that plastic coating, and exposing
01:18the contents to the metal are pretty, pretty low.
01:21Despite protective lining, some people still think there's a metal taste.
01:26I actually think it tastes like cans.
01:28Sometimes cans can taste a little bit metallic.
01:31So, where is this sensation coming from?
01:33Your tongue is very sensitive to metal.
01:36The one time when the product is exposed to the metal itself is when the cans open.
01:42You put your tongue on a metal can, it's entirely possible, especially people who are sensitive
01:47to it, there would be just enough to come off to change the way things tasted on their
01:52tongue.
01:52Plastic bottles are typically made with PET, or polyethylene terephthalate.
01:58While both cans and plastic bottles contain chemicals you probably wouldn't want to consume
02:03in large quantities, they are perfectly safe to drink out of.
02:06All containers that they use, glass, plastic, metal, have been extensively tested for what
02:14will leach into the liquid that's put in them.
02:18The FDA also regulates the amount of contaminants allowed in drinks to make sure they're safe.
02:23But humans have been known to detect even minute amounts of contaminants.
02:26According to Christy Spackman, a researcher at Harvey Mudd College who studies taste.
02:32Here it's useful to remember that zero is not always zero.
02:35People can detect certain things at levels well below instrumental detection.
02:40It depends on the molecule and it depends on the human.
02:43So while unlikely, it's possible that even the slightest bit of contamination might affect
02:48the taste for some.
02:49Now let's take a look at carbonation.
02:53Humans taste carbonation using the same taste receptors that recognize sour foods, according
02:59to a 2009 study by Science Magazine.
03:01And we can also detect carbonation from soda in another way.
03:05When you drink it, you get two things going on.
03:07One is you get that tingly thing from the bubble, but you also get that carbon dioxide going up
03:13in your nose that carries the other flavors into your nose as well.
03:18So carbonation levels can affect the taste.
03:21But how can the CO2 levels change based on the packaging?
03:24So carbonation can slowly potentially leak out of a plastic bottle in a way it can leak out of a
03:31glass bottle.
03:32That's assuming they've both been appropriated to be sealed.
03:35The structure of the glass is pretty tight.
03:38Okay.
03:38It's like a really tight mesh rather than a loose mesh.
03:42The diffusion rates of glass are really, really soft.
03:44And in metal, it's the same thing.
03:46But most bottles are typically designed to prevent CO2 from escaping quickly.
03:50A plastic bottle is a multi-layer thing.
03:53Some of them provide rigidity and some of them provide a barrier to the oxygen going in and the CO2
03:58coming out.
03:59And then there's a final barrier that just protects the contents.
04:02And if the container is warm, more CO2 will be released when you open it, making the soda taste flat.
04:09Light can also affect flavor, assuming the bottle does not contain any light protective layers.
04:14Light can cause chemical reactions to occur, and so some of the substances in there may change some of the
04:19flavor compounds.
04:20A lot of the flavor compounds are really, they're subtle molecules.
04:24They're the sort of things that can really, a little change can change their flavor a lot.
04:29So how a soda is stored can prevent any rapid alteration in taste.
04:33So something that's bottled in glass and stored away from light is going to have a flavor profile that can
04:39last much longer,
04:40and also carbonation levels that will stay consistent much longer than something in plastic.
04:46But there's also more to taste than what happens on a molecular level.
04:52Spackman says experience can also affect the way we taste.
04:55People who drink Diet Coke a lot every day, for example, might be able to tell a difference more than
05:00someone else.
05:01And so they have a sensory awareness just because their memory is so constantly being refreshed about what a sensory
05:08experience is like.
05:09It's really hard to separate the objective and subjective sides to taste.
05:16What we taste sometimes isn't as much affected by what we expect as what's actually there.
05:24So soda drinkers aren't likely to change their habits anytime soon.
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