- Pickling, that salty, briny process that makes food stay so, oh, weirdly good.

I'm Sheril Kirshenbaum and on this episode of Serving Up Science, we are exploring the science and history of pickles.

The word pickle comes from the Dutch pekel or Northern German pokel, meaning brine.

(funky music) Pickling is the process of adding acid to, or producing acid through, the controlled fermentation of vegetables.

(tapping jar lid) Fermentation is the chemical breakdown of a substance by bacteria, yeast, or other tiny living things.

(tapping jar lid) A hammer would be better.

And these little suckers are created by immersing different foods in acidic liquid, or brine, which is essentially salty water, until they're no longer considered raw.

Like cucumbers, asparagus, onions, carrots, cabbage, eggs, watermelon rinds, pig's feet, beets, garlic, kimchi, peppers.

I don't know, guys.

Someone needs to write me a list.

I need a drink.

No, I don't.

And okay, in North America, the word pickle typically refers to a pickled cucumber.

Now, how exactly does a pickle become a pickle?

Here's the science.

The brine, that salty solution, produces lactic acid and other antibacterial substances.

But it leaves the good stuff behind, like nutrients.

Germs that can make us sick can't tolerate high salt concentrations, so they're outta here.

You can also use vinegar instead of brine, and that works in a similar way, but produces a different taste.

Vinegar lowers the pH of the mixture to a level where a lack of oxygen prevents the growth of germs.

Both of these methods for pickling impact the texture and flavor, as well as the look.

I'm talking about, well, color and shrinkage.

Cucumbers are green, thanks to chlorophyll, which gives plants their bright color.

But the brine or vinegar used in pickling replaces a magnesium atom with a hydrogen atom and that just transforms the natural emerald color to olive.

And of course, as I said, pickles get a lot smaller, and that's because of the process of osmosis.

The high concentration of salt in the solution causes a lot of the water to rush out of the cucumber and that makes it shrink.

Today, pickles themselves are usually an afterthought or a garnish for many of us.

But pickling was born out of necessity thousands of years ago.

Our ancestors couldn't exactly store leftovers in the fridge or freezer.

So, they were in, well, a pickle, dealing with the spoiled food which frequently led to dangerous illnesses.

And it's not like they could get antibiotics or pop some of the pink stuff when things went south.

The consequences of eating rotten foods could be deadly.

They still are, today.

Pickling began a long time ago, in a galaxy far, far away, Ancient Mesopotamia.

Foods were pickled for storage, convenience, and simply because we didn't have many other options.

It was the way to be able to enjoy out-of-season vegetables and fruits all year round.

While pickles were originally created so foods wouldn't spoil, we continue the practice today because we like the way they taste.

Pickles also came into favor as one of the earliest travel foods.

Sailors could safely store pickled fruits and vegetables to satisfy hunger quickly in route to who knows where, without additional prep.

And pickled foods spring up in surprising ways throughout history.

Queen Cleopatra, legendary for her beauty, credited pickles with contributing to her health and looks.

And the logic isn't all that far-fetched.

We're preserving our foods through pickling, so why not preserve our bodies that way?

Of course, she couldn't have visited a department store cosmetics counter, so hey, I give her credit for creativity.

Around the same time, Roman emperors believed that eating pickles would make their soldiers strong.

And later, Napoleon held a similar notion.

In fact, Shakespeare references pickles in many of his plays, like Hamlet and Twelfth Night, and Christopher Columbus, he brought them on his journey when pickles were understood to prevent scurvy.

So, pickling and pickles have been eaten and celebrated for thousands of years, and we continue to enjoy them today.

Here is the important part.

When pickling, don't go rogue.

You absolutely do not want to change the vinegar, food, or water proportions in any pickling recipe you might try.

Why?

Well, it all goes back to safety, which is the reason we started pickling in the first place.

You need to create a minimum uniform level of acid throughout the mixture to prevent the growth of bad bacteria that can make us sick.

So, make sure to follow the recipe.

But, after that, it's pretty simple.

And, you get to enjoy the non-spoiled fruits or vegetables of your labor.

Peter Piper picked a peck of pickled peppers.

A peck of pickled peppers Peter Piper picked.

If Peter Piper picked a peck of pickled peppers, where is the peck of pickled peppers Peter Piper picked?

(crew members cheer and applaud) (dramatic music)