When I buy coffee from outside, from whatever popular brand outside, and drink it, I feel a bit elevated. Especially one with higher caffeine content.
However, when I drink the one I make my own I feel a bit more neutral/ have a headache depending on how much instant coffee powder I use. I am so confused on this because to my understanding, both the restaurant and I are using more or less the same ingredient: Coffee beans. So why does one lead me to be elated while the other gives me a headache?
Here is my preparation currently: Powder and sugar in cup, hot milk in, mix to serve. Definitely not the most sophisticated kind of preparation but I think the chemical composition of the ultimate product should be comparable, hence the effect of drinking.
I'm aware of Why are Costa or Starbucks lattes so good?, though that question is aimed at improving coffee at home. In this question, I'm interested in a comparison of instant coffee and espresso-based coffee.