In search of an answer, we had an appointment with the young couple - Ms. Ho Thi Thanh Huong and Mr. Tran Nguyen Huu Phong - who "invented" and "brought" salted coffee to CNN.

Salted Coffee Shop (142 Dang Thai Than, Hue City) welcomed us on a rare sunny winter afternoon in Hue. Right in front of the alley with a wall covered with thick green vines is a "Salted Coffee" sign on raw wood, designed by Ms. Thanh Huong - an architect - when the shop was first established about 10 years ago. Time, rain and sunshine in Hue have made the sign old and rotten, but the owner has not had the heart to replace it with a new one.

Nestled in a peaceful green garden just a street width away from Hue Imperial Citadel, the space of Salted Coffee shop is so quiet that you can hear the footsteps of customers on the path. Even the conversations of customers are very small. You have to listen carefully to know whether they come from Hanoi, Saigon, Japan, Korea, France...

Feeling relaxed, Mr. Ike Tort - a tourist from Australia - chose a suitable seat for himself. “I was in Hoi An. I drank salted coffee there every day. I also tasted coffee in many places in Vietnam. But here, this salted coffee makes me forget whatever I drank before.” Mr. Tort confided, with a cup of coffee in his hand.

The Happiness of the Salted Coffee couple

Talking about the “trip” of salted coffee to CNN, Mr. Phong said: Almost a year ago, through his Salt Coffee fanpage, a CNN reporter contacted him to write an article about the phenomenon of Vietnamese salted coffee that caused a “fever” in the US, to the point that many Americans tried to adjust their coffee to resemble this drink.

After the article, the whole world learned that the famous salted coffee of Vietnam originated from Hue. CNN’s discovery urged many tourists like Mr. Tort to come to Hue, just to enjoy a cup of authentic salted coffee.

Regarding Salted Coffee Shop which has become his “global citizen”, Mr. Phong said that in 2014, he and his wife decided to open the first coffee shop at 10 Nguyen Luong Bang - Hue. “When being a student, my wife was very passionate about coffee. In nearly 10 years of knowing each other, it seems like there was  no coffee shop she had not visited to explore and experience”. Mr. Phong opened up about the reason why Ms. Huong - a former physics student of Quoc Hoc High School for the Gifted - Hue, an architect, decided to quit her job to open a coffee shop.

“We chose to name the shop Salted Coffee, but at that time, the menu did not include salted coffee. We also never knew what salted coffee was and had no idea about salted coffee. It was not until many customers asked if the salted coffee shop had salted coffee that we came up with the idea: Why don’t we try making salted coffee?”, Mr. Phong recalled.

With coffee, condensed milk, fermented fresh milk and salt, salted coffee - a Hue drink on CNN

Recalling her first cups of salted coffee, Ms. Huong shyly said: “Only when regular customers came, I dared to ask them to try it. Some said it was too bitter. Some said it was too salty. Some said it was too sweet, but I didn’t know how much was “too much” to reduce.” To decipher that “right” amount, Ms. Huong had to spend more than a year researching on her own, using all her accumulated “coffee experience” and countless experimental cups of coffee. Finally, with patience, intuition and love..., Ms. Huong “invented” a recipe for making salted coffee that changed the world’s thousands of years of coffee “taste”.

A recipe in which, from choosing coffee beans to roast and grind, fermenting fresh cream, and making salt into ingredients for mixing, are all secrets. A balance that makes visitors feel strange, try it to know, fall in love and become addicted without realizing it. With that success, at the end of 2014, Salted Coffee opened a second new shop in Hue Citadel area.

In a story that is no longer limited by the inherent privacy of Hue people, Mr. Phong said that up to now, his salted coffee has received many invitations to cooperate, franchise, and open branches. There are opportunities but they all "shake their heads". "We just want to keep our salted coffee for Hue alone. If someone loves it, they have to find it in Hue. Salted coffee has brought Hue to far away places. Now that we hope salted coffee will bring the whole world to Hue, like Hue mussel rice, or Hue beef noodle soup...". Mr. Phong confided about a "selfishness" that is the nature of Hue people, when they conservatively hold on to what they love so much. For Mr. Phong and Ms. Huong, it is the love of coffee and a deep love of Hue.

As for me, on a cold winter afternoon, I was lucky enough to be personally “served” a cup of authentic salted coffee by Ms. Huong, and I understood why Hue’s coffee is so famous. It was like touching the sun and wind of the Central Highlands in the slightly bitter taste of Ban Me coffee beans; feeling the coolness of the Huong River water as if still smelling the aroma of the calamus; feeling the saltiness of the sea crystallized in a cup of coffee that was just sweet enough, just bitter enough, just fragrant enough, just salty enough... An emotion that Ms. Huong said: It can only be the taste of love.

And Hue has something more special for someone to get back ...