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PICKLING: HOW DOES IT HAPPEN?

by Luke Shen

The Question

When it comes to the perfect accompaniment to any food, pickles reign supreme. From pickled cucumbers to pickled radish, what exactly makes pickles, pickles?

The Definition

To answer this question, we first need to know what a pickle is. According to the Michigan State University’s definition, “Pickling is defined as the process of preserving a food by either anaerobic fermentation in brine or immersion in vinegar. The resulting food is called a pickle.” Put simply, the key to making a pickle is putting the food through a process known as anaerobic fermentation. Anaerobic means “living, active, occurring or existing in the absence of free oxygen”, so with this in mind, anaerobic fermentation is fermentation that occurs without oxygen.

The History

The process known as pickling dates back over 4000 years ago! The Mesopotamians soaked their cucumbers in acidic brine to preserve their cucumbers so that they could create a vinegary, crunchy treat. Cleopatra’s beauty is often associated with her consumption of pickles. Her respect for pickles also spread to Rome, where the emperors’ distributed pickles to their soldiers to make them stronger. In fact, Amerigo Vespucci, the man known for being the namesake of America, was also known to be a pickle distributor to sailors exploring the New World. Explorers of the New World brought pickles in their journeys because they prevented scurvy.

 The Family

There are several different foods under the category of “pickle”. Foods such as pickles (the cucumber), beni-shoga (pickled ginger), sauerkraut (pickled cabbage), kimchi (an assortment of pickled cabbage and spices) are the most well-known. The main goal of pickling is to grow the lactobacilli , a bacterium that produces lactic acid from the fermentation of carbohydrates. The lactic acid is what gives pickled foods its signature sour flavor (in a good way). Essentially, this process is a battle against spoilage microbes (bacteria that causes your food to spoil).

The Process

 Several factors go into preventing spoilage. First off, it’s important to distinguish that the lactobacilli are bacteria that are beneficial to us. Their main goal is to consume the sugars of the food being pickled before the spoilage bacteria — a food eating competition of sorts. As mentioned before, the byproduct from the lactobacilli’s consumption of sugar is the lactic acid.  To keep our friendly bacteria ahead of the game, we provide several factors to aid in their victory. The submerging of the food into vinegar is the first step. The reason why vinegar is helpful is because it increases the acidity of the food, which kills a good amount of the spoilage bacteria. It’s just important to maintain a 5% acetic acid in the vinegar so that it can kill the bacteria in the first place. Also, by putting the food into the vinegar, the spoilage bacteria are isolated from the oxygen in the air. This is good because an important factor in the growth of bacteria is oxygen. Placing the food in the vinegar means less oxygen for the spoilage bacteria to work with. Secondly, the use of salt in pickling not only is responsible for the texture and extra flavor in the food, but also provides the lactobacilli with a growth advantage. This is because of how salt will put most bacteria into osmotic shock, leading to water loss and death. However, salt only slightly slows the growth of lactobacilli, giving it a growth advantage. As long as you maintain the proper concentration, the salt will filter out the spoilage bacteria, leaving the lactobacilli to produce their lactic acid. This combination of factors allows the food to be preserved, flavorful, resulting in a delicious, nutritious treat!

The Shortcut

However, this overall process takes around six weeks for a proper brining of a pickle, and time is money, especially for pickle companies. Nowadays, to speed up the process, most will pasteurize the pickles. This means heating up a batch of pickles in a giant vat so that all bacteria are killed off (including our friendly lactobacilli). The result is a completely sterile cucumber that is ready to be processed with artificial stuff, packaged in a jar, and shipped off to your local supermarket. Even though this process is faster, this does lead to pickles with a shorter shelf life. 

The Summary

Long story short, pickles are foods that are put through the process of anaerobic fermentation. During this process, the main aid in the creation of pickles is lactobacilli, a friendly bacteria that provides pickles with its signature sour flavor. In order to help our friendly bacteria, ingredients such as salt and vinegar are used to make the friendly bacteria population grow faster than the bad, spoilage bacteria. 

And that is what makes pickles, pickles! 

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