I was asking a blanket question on the /askfoodhistorians when I came across this wonderful answer below by u/wotan_weevil
However, I also came across this article saying that There are many books that mention the cultivation of gochu on the Korean peninsula, 2000 years ago.
That article is basically nonsense. A brief sampling of some of the wrong statements:
"Biologically, Korean gochu is different from the red peppers of Central American countries (such as Mexico and Colombia), Indonesia, India, and Thailand." In a strict sense, this is quite true. The Korean variety, while the same species as most chillies (and capsicums), Capsicum annuum, is a distinct variety. But the difference is small, and the difference overwhelmingly suggests just a few centuries of post-Columbian selection, rather than the million or so years the authors want it to mean.
Statements like " kimchi can be made using gochu only" combine two incorrect claims. First, that chillies are necessary for the fermentation process, which is simply wrong, as can be seen by modern and historical Korean varieties of kimchi that use no chillies (e.g., white kimchi AKA baek kimchi) and similar fermented foods such as sauerkraut. Second, other chilli varieties can be used, as long as the amount is appropriate. Noting that Korean chillies appear to have been bred to become much milder during the 20th century, and used in much larger amounts, with the amount in kimchi recipes increasing during the 20th century by about 14 times, this argument from the mildness of modern Korean chillies says little about older varieties of Korean chillies.
The authors have elsewhere https://doi.org/10.1016/j.jef.2017.08.010 stated that
There are similar nationalism-over-science/history claims about other things in Korea. For example, one can easily find claims that taekwondo is a 5,000 year old Korean native martial art, in contradiction to the historical facts (that it developed from (mostly) Japanese karate in the 1950s).
For more detail see this earlier discussion about Korean chillies:
which includes an excellent answer by u/PangeranDipanagara and in which this paper was mentioned, I commented on this paper: