Before foreign coffee chains covered the Chinese market, domestic coffee was mainly instant. It wasn't until foreign chain brands covered the Chinese market with espresso that instant coffee began to decline and freeze-dried coffee began to rise.
The use of the two is much the same, they are mixed with hot water to be drunk directly, and both belong to a kind of convenient coffee, which makes people wonder, are they the same thing with a different name?
Although they are all products born around the concept of convenience, and they are all a kind of convenient coffee, there are still certain differences between the two, let's start with instant coffee!
The birth of instant coffeeIn the 18th century, during the American Revolutionary War, soldiers were almost madly obsessed with a refreshing drink - coffee, even to the point that it was difficult to walk without coffee! Therefore, one of the most common sights on the march is that as soon as the soldiers catch a gap, they will fill a pot of coffee and drink it to their heart's content.
However, since the troops distributed coffee beans that had not yet been ground, the soldiers would grind them first and then brew the ground coffee particles into coffee every time they needed to drink it, which was very time-consuming.
This almost crazy move reached the U.S. Congress, and in order to prevent soldiers from spending too much time and energy on drinking coffee, the U.S. Congress began a study called "Easy Portable Coffee." Then, with the strong sponsorship of Congress, at the end of 1861, a product called Coffee Essence was born.
According to the inventor, this coffee essence is obtained by mixing coffee, milk, and sugar and then concentrating it! With just a small spoon, it becomes a delicious pot of coffee when mixed with water, and the weight and volume are greatly reduced, making it very portable! 
That's what they say, but the American soldiers didn't buy it! The taste of this essence is very unpleasant, unrefreshing, and it may be made with spoiled milk, which causes many soldiers to have diarrhea on the spot after drinking it! This series of negative instances soon led to the discontinuation of this coffee essence. Although it was discontinued, it also made all businessmen smell a huge business opportunity and invest in the production of portable coffee!
In 1890, D**idstrang, who sold coffee and spices in New Zealand's South Island, produced soluble ground coffee by hot jet coffee liquid and named it Strong Coffee. That's right, this soluble ground coffee is the world's first true instant coffee. 
In 1899, Satori Kato, a Japanese chemist, made instant coffee by extracting the dried powder of a coffee solution dried under vacuum drying, and in 1903 he patented the technology. But at this time, he did not realize the journey of the product to be commercialized. So in 1906, George C. Washingtonl.Washington) obtained a patent for the production of instant coffee in the United States, and produced "Red E Coffee", a commercial instant coffee, which was vigorously promoted to the market. But in the end, "red e coffee" didn't spread around the world because of its poor taste.
Until 1929, Brazil was stranded with a large number of coffee beans due to the economic crisis! To solve this problem, the Brazilian Coffee Research Institute applied to Nestlé in Switzerland to develop instant coffee with a more concrete taste. 
It took Nestlé eight years to invent the "spray-dry method" in 1937, which first extracts the substances from the coffee beans, and then uses hot air to evaporate the water in the coffee to dry the coffee from the liquid into a powder, and adds soluble carbohydrates to the drying process to increase its flavor. And just like that, more convenient instant coffee was born!
However, the disadvantage is also obvious, due to the continuous high temperature drying, the aromatic substances in the coffee are almost volatilized, and all that remains is the bitter component. Therefore, instant coffee is usually made with the poor-tasting Robusta beans, and then a large amount of non-dairy creamer and sugar are added to dilute the bitterness. That's why instant is synonymous with "low-end coffee," because early instant isn't healthy.
While promoting instant dissolution, people are also constantly researching and innovating. Subsequently, it was discovered in 1935 that in 1935 it was discovered by Dr. Staurt Mudd and Dr. Vlossdorf earl w.Flosdorf's freeze drying technology was applied to food production, and the Shears brothers used freeze-drying technology to make freeze-dried coffee, which was awarded 47 U.S. and foreign patents between 1966 and 1971. 
Freeze-dried coffee is similar to instant coffee, both of which are the first to extract the substances in the coffee beans! However, the freeze-dried coffee liquid is not as thin as we normally would, but very thick, similar to chocolate liquor. Immediately after extraction, the liquid is transported to -5°C for condensation until it becomes a paste and then transferred to a freezer below -40°C for freezing! After freezing into blocks, they are directly crushed into small pieces of 2 3mm. 
Finally, these cubes of coffee are sent to the vacuum drying chamber for heating and drying, and when heated in a vacuum, the water will sublimate instead of liquefy, and the dried coffee particles are what we see as freeze-dried coffee today!
Because it is cooled immediately after extraction, the freeze-dried coffee retains more of the coffee flavor and allows for the replacement of Robusta with better Arabica beans. Of course, this is followed by increasing costs due to complex processes and expensive materials. 
Speaking of which, it seems that we have already got the answer, the reason why what we think of as instant coffee is often defined by coffee players as the bottom of the "contempt chain" is because of its craftsmanship and materials that make it unpalatable. And long-standing stereotypes also make it difficult for the word to associate with good taste. Therefore, when instant appeared in front of people with a "new look (freeze-dried coffee) and a new connotation (using better materials)", it gained the ability to be sought after again.