Healthy, fermented foods are matured by time. Every nation has its own fermented food that has been guarding the people's health for centuries. Korea's kimchi, in particular, is receiving the global spotlight as an enriching, well-being food. At the start of winter, every household in Korea makes gimjang kimchi. The major ingredients are napa cabbage and radishes, seasoned with red pepper powder, various vegetables, and salted seafood. The flavor of the kimchi is determined by the level of fermentation. Over the course of the year, this kimchi will act as an important source of nutrients that are often lacking in the modern diet. Kimchi is made in a large batch in winter. But aside from then, kimchi can be made anytime, with any seasonal vegetables, and appear in many different forms according to the local climate and preferences. Seaside regions use salted seafood in its seasoning, while warmer regions make kimchi that emphasizes spicy and salty flavors. The most well-known type of kimchi is napa cabbage kimchi, known as baechu kimchi. It has the shortest history of any kimchi varieties, and yet, it is the most dominant type in Korea and around the world. It was first made with red peppers that entered Korea in the 16th century and modified cabbage that appeared in the early 1900s. It has only been around in its current form for about a hundred years. Despite its short history, baechu kimchi has become iconic because it is the ideal type for fermentation. From the freshly made geotjeori to aged mugeunji, baechu kimchi can be enjoyed in myriad ways. In the past, kimchi was stored in onggi (earthen jars) buried underground because a stable environment was crucial to good kimchi. Now, specialized kimchi refrigerators that recreate the underground environment have become ubiquitous in Korean homes. For Koreans, storing kimchi is just as important as making it.
So after the napa cabbage leaves, after they're seasoned,
they're wrapped tightly.
And this is for two reasons.
One, it's to keep as much of the air out as possible.
It keeps the good bacteria in and the bad bacteria out.
And two, it helps it to ferment evenly.
And now, the longer you ferment kimchi,
the stronger, more complex the flavors become.
And it's for this reason that kimchi is now considered
a nutritional food around the world.
Then, what's the nutritional value
of the everyday kimchi that Koreans eat?
To make kimchi, you must first prepare basic ingredients.
Red pepper powder, garlic, radish,
pickled seafood, salt, and ginger.
Only when each of these ingredients
plays its role during fermentation
can kimchi acquire its fine taste.
A few years ago, when the SARS epidemic broke out,
the global press took note of Korean kimchi.
They reported that kimchi protected Koreans
from SARS and avian flu,
and lowered the incidence of obesity
and lifestyle diseases as well.
Is kimchi really so powerful
that it can give protection against epidemics?
Let's take a look at each ingredient.
Red pepper powder has anti-carcinogenic
and anti-oxidizing effects, and improves metabolism.
It also prevents food from spoiling.
Garlic inhibits the activities of harmful viruses,
strengthens the immune system, and alleviates fatigue.
Ginger has powerful antibacterial effects
and prevents lifestyle diseases.
The main ingredient, napa cabbage,
also an anti-carcinogen,
lowers the blood cholesterol level.
Delicious and nutritious,
Korean kimchi is the full package.
It boosts the immune system
and helps the body stand up to the stress of everyday life.
In the past, Koreans preserved their kimchi
in earthen jars buried underground
to enhance the nutrition and flavor of kimchi.
To make the best kimchi,
or to make the best anything for that matter,
you need to start with the best ingredients.
For example, the best baechu kimchi
requires the best napa cabbage
for that crunchy texture and that natural sweetness.
Now,
freshly made kimchi retains all the flavors
of its original ingredients,
but this, this is mugunji, it's aged kimchi,
and it's been fermented for a while.
And the fermentation process requires you
to control time and temperature,
which is why Koreans are fastidious
about how they store their kimchi.
I mean, there are even special refrigerators for it.
So, what's the theory behind this?
Kimchi is matured by nature.
Time alone cannot produce kimchi's rich taste.
Unlike other foods, kimchi requires special storage.
Traditionally, during the gimjang season,
while women made kimchi,
men would dig holes in the ground
and get the earthen jars ready.
The constant temperature underground
created an ideal condition for fermentation.
Koreans put more effort into storing kimchi
than making it,
because the fermentation process is largely dependent
on the storage container and environment.
How big a difference
do the different storage containers make?
We conducted a test with a specialized kimchi container,
a glass container, an earthen jar, and a plastic container.
After two weeks, how different was the kimchi?
We analyzed each sample for smell, acidity, and texture,
all of which changed during fermentation.
We found that kimchi stored in the specialized container
measured the highest in terms of sourness and crispness,
the signs of fermentation.
The fermentation of kimchi depends on the oxygen
and carbon dioxide that enter the container.
The best kimchi containers block out oxygen,
while maintaining a constant level of carbon dioxide.
The practice of storing kimchi underground fell out of trend
as Korea rapidly became urbanized.
What came instead was the kimchi refrigerator,
which recreates the underground environment.
It is now as common a household appliance
as the regular refrigerator.
Kimchi stored in ordinary refrigerators
often goes sour before fermentation can fully take place,
but kimchi refrigerators keep kimchi fresh
and the fermentation process under control.
The storage temperature for kimchi
is zero to negative one degrees Celsius.
Aged over time at this temperature,
kimchi retains its crunchy texture and rich flavor.
The storage space is divided into sections
to allow for different types of kimchi,
and the temperatures within the refrigerator
vary by less than one degree Celsius.
The conditions are almost identical to those below ground.
In regular refrigerators,
the temperature can vary by up to three degrees,
but with kimchi refrigerators,
the internal temperature is almost constant.
This is crucial to the flavor and fermentation of kimchi.
Kimchi refrigerators ensure
that fermentation takes place evenly.
Also, the specialized containers
help keep the temperatures constant.
