title_body: Vietnamese coffee from concentrate?
upvoted_answer: Apparently they used some sort of a pour over method, I'm not very sure about it though because they wouldn't expose their trade secrets to me ;). 
  
  What I am sure is it is common practice for the Vietnamese to sell from concentrate, because they brew a batch in one go then refrigerate it until it is used, not unlike cold brews. If you're a fan of espresso, you can drink the concentrate straight up.
  
  Source: A Vietnamese coffee seller during a trip