WEBVTT - BrainStuff Classics: How Does Salt Prevent Food Spoilage?

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<v Speaker 1>Welcome to brain Stuff, a production of I Heart Radio.

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<v Speaker 1>Hey brain Stuff, Lauren Vogel Bomb here with another classic

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<v Speaker 1>episode from our archives. As we're in the midst of

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<v Speaker 1>the fall season here in the United States, many people

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<v Speaker 1>are starting to think about holiday feasts, perhaps including a

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<v Speaker 1>brined turkey or a ham cured with salt. Aside from

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<v Speaker 1>being tasty, these preparations helped preserve meat. Here's why, Hey

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<v Speaker 1>brain Stuff, Lauren Vogel bam here, let's talk salt. You

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<v Speaker 1>might toss a little over your left shoulder for good luck,

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<v Speaker 1>sprinkle some on your eggs, or even tip a shaker

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<v Speaker 1>into a frothy beer. However you use it, one thing's

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<v Speaker 1>for certain. Most of us take salt for granted. Salt

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<v Speaker 1>wasn't always such a simple matter. For centuries, it was

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<v Speaker 1>a rare commodity, used as payment, as an impetus for wars,

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<v Speaker 1>and often for survival. Salt preserved fish and ancient Egypt

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<v Speaker 1>seasoned Roman salad dressings, and even came to stand for

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<v Speaker 1>a measure of a person's integrity. A competent Roman soldier

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<v Speaker 1>was worth his salt, had earned his allowance of the

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<v Speaker 1>valuable seasoning. But more than being tasty, salt kept entire

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<v Speaker 1>civilizations alive thanks to his ability to prevent foods from

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<v Speaker 1>turning into bacterial Latin killers. To understand how salt prevents

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<v Speaker 1>foods from spoiling, it's important to first grasp how it's

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<v Speaker 1>used to preserve foods. Salt is used in two primary ways,

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<v Speaker 1>either in granule form or in brine form, a brine

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<v Speaker 1>being a water and salt solution. A ham, for example,

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<v Speaker 1>might be cured with salt, and cucumbers are preserved and

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<v Speaker 1>turned into pickles with brine. Curing with salt granules, known

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<v Speaker 1>as dry curing, means applying salt to the outside of

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<v Speaker 1>a cut of meat and storing it for a couple

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<v Speaker 1>of days up to several weeks. It's one of the

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<v Speaker 1>most ancient ways of curing meats. Modern curing can involve

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<v Speaker 1>injecting meat with salt brine. Whatever the form of salt

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<v Speaker 1>it's used, the mineral preserves foods and makes them safer

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<v Speaker 1>to eat by preventing bacteria from growing, including the bacteria

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<v Speaker 1>that break down rotting food and also food board pathogens

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<v Speaker 1>such as salmonella, which can cause food poisoning, typhoid eiver,

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<v Speaker 1>and other serious problems. Salt inhibits bacteria in a variety

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<v Speaker 1>of ways. It's a disruptor that reeks havoc in microbes,

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<v Speaker 1>interrupting their enzymes and chipping away at their DNA. It

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<v Speaker 1>most often works through dehydration, though removing many of the

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<v Speaker 1>water molecules the bacteria need to live and grow. Water

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<v Speaker 1>molecules and food are measured in terms of product water activity,

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<v Speaker 1>a number that signifies the free water molecules present before

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<v Speaker 1>salt preservation. Many fresh foods have point nine nine product

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<v Speaker 1>water activity. The product water activity is lowered when salt

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<v Speaker 1>dehydrates the food through the process of lasmosis. In essence,

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<v Speaker 1>the salt around the outside of the food draws water

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<v Speaker 1>molecules out and replaces them with salt molecules until the

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<v Speaker 1>amount of salt is equal inside and out, lowering the

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<v Speaker 1>water product activity to point nine Ford point nine one

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<v Speaker 1>is usually sufficient to prevent most bacterial growth. Today's episode

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<v Speaker 1>was written by Laurie L. Dove and produced by Tristan

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<v Speaker 1>McNeil Entiler Clang. For more on this lots of other topics,

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<v Speaker 1>visit how stuff works dot com. Brain Stuff is production

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<v Speaker 1>of iHeart Radio. For more podcasts from my Heart Radio,

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