WEBVTT - BrainStuff Classics: Skim Versus Whole Milk: Which Spoils Faster?

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<v Speaker 1>Welcome to brain Stuff, a production of iHeartRadio. Hi brain Stuff.

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<v Speaker 1>I'm Lorn vogel Bomb, and this is another classic episode

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<v Speaker 1>from the Vault. This one gets into the science behind

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<v Speaker 1>the expiration dates on different types of milk, or rather

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<v Speaker 1>the lack of science. It turns out it's really more

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<v Speaker 1>of a suggestion at best. Hey, brain Stuff, I'm Lauren

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<v Speaker 1>vogel Bomb. And we've all had moments of uncertainty and

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<v Speaker 1>let's face it, paranoia about the state of the food

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<v Speaker 1>sitting in our refrigerators. You might be able to eyeball

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<v Speaker 1>some of those suspicious items, check for expiration dates on others,

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<v Speaker 1>and with some milk maybe you'll probably take a quick

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<v Speaker 1>with and hope for the best. But if you've ever

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<v Speaker 1>looked a shelf life chart to figure out how long

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<v Speaker 1>your milk might last, you might have noticed that skim

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<v Speaker 1>milk is said to last a day or two longer

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<v Speaker 1>than whole milk. But is that really true and if so, why?

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<v Speaker 1>Before we really get started, I should state that there

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<v Speaker 1>is by no means universal agreement on this issue. Some

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<v Speaker 1>dairy scientists say skim milk lasts longer because certain fat

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<v Speaker 1>loving microbes can't develop as quickly in non fat milk.

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<v Speaker 1>Others say that whole milk lasts longer because free fatty

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<v Speaker 1>acids might actually be natural preservatives. Still, others say that

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<v Speaker 1>maybe there isn't a difference in spoilage at all, it's

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<v Speaker 1>just that we notice flavor changes more in one or

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<v Speaker 1>the other. There's only been one major controlled study on

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<v Speaker 1>these spoilage rates of whole and skim milk, and it

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<v Speaker 1>was somewhat inconclusive. Skim milk was found to spoil slightly faster,

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<v Speaker 1>but the researchers weren't exactly sure why. Bacteria that are

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<v Speaker 1>psychotrophic that is, cold resistant, are what caused spoilage in

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<v Speaker 1>the fridge, and in the study, they multiplied at the

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<v Speaker 1>same rate in both types of milk. When the milk spoiled.

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<v Speaker 1>Both whole and skim contained similar strains of bacteria. There

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<v Speaker 1>is a pronounced difference in how whole and skim milk

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<v Speaker 1>reacts did when they were injected with the same spoilage microorganisms,

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<v Speaker 1>but they affected the milk's taste and smell more than

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<v Speaker 1>they did the actual spoilage rate. Whole milk, for the record,

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<v Speaker 1>tended to turn sour and skim milk was on the

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<v Speaker 1>bitter side, So for the purposes of your average milk consumer,

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<v Speaker 1>there's really no hard and fast rule about which kind

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<v Speaker 1>will spoil faster. If whole milk does last longer than skim,

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<v Speaker 1>the difference is so slight that any given gallon of

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<v Speaker 1>skim milk could outlast any given gallon of whole milk.

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<v Speaker 1>The spoilage rate depends on so many variables manufacturer production methods,

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<v Speaker 1>milk formulation, plant sanitation, storage temperatures, pH level, moisture content,

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<v Speaker 1>just to name a few. A small change in just

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<v Speaker 1>one of them could give any particular container of milk

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<v Speaker 1>a slightly longer shelf life than another. A couple other

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<v Speaker 1>factors make things even more ambiguous. For one, it's pretty

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<v Speaker 1>much impossible to pinpoint the exact moment of spoilage. Depending

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<v Speaker 1>on your sense of smell and taste and your tolerance

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<v Speaker 1>for changes and milk flavor, you might turn up your

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<v Speaker 1>nose at a gallon of milk that someone else might

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<v Speaker 1>readily swig. And there's no federal regulation of milk expiration

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<v Speaker 1>dates in the United States. Only twenty states legally standardize

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<v Speaker 1>the date that's printed on the bottle, and those standards

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<v Speaker 1>very widely. One state might mandate a cell by date

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<v Speaker 1>of a certain number of days after pasteurization, whereas milk

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<v Speaker 1>jugs in another state would be printed with a use

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<v Speaker 1>by date. The upshot don't base your milk purchases on

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<v Speaker 1>which type might last longer. If you're concerned about shelf life,

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<v Speaker 1>you'd be better off following a few simple steps to

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<v Speaker 1>slow down milk spoilage, whether you're a whole or skim drinker. First,

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<v Speaker 1>make sure your refrigerator is the correct temperature. It should

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<v Speaker 1>be set at forty degrees fahrenheit that's four point four

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<v Speaker 1>degrees celsius. Store your milk on an interior shelf instead

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<v Speaker 1>of on the door, which fluctuates more in temperature. And

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<v Speaker 1>make sure you put your milk back in the fridge

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<v Speaker 1>as soon as possible after using it. Leaving it out

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<v Speaker 1>on the counter for even a few minutes exposes it

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<v Speaker 1>to light and heat, giving bacteria a chance to spring

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<v Speaker 1>into action. Today's episode is based on the article does

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<v Speaker 1>whole milk spoil faster than skim milk? On how stuffworks

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<v Speaker 1>dot com, written by Alison Cooper. Brain Stuff is production

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<v Speaker 1>of by Heart Radio in partnership with how Stuffworks dot

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<v Speaker 1>com and is produced by Tyler Klaang. For four more

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<v Speaker 1>podcasts from my Heart Radio, visit the iHeartRadio app, Apple Podcasts,

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