Need some help here. I haven't try how a good espresso shot should taste like. I've tried shots that I pulled but comparing to what I read from other articles, I don't think it came anywhere close to what some call a 'god shot'.

My shots taste bitter and sometimes sour, strong bodied yes. What I read was that good espresso shots don't taste bitter or sour at all. Some would put it that the shots should taste like a concentrated scent of the bean, only that it would be tasted with your tongue instead of nose.

I went to some claimed 'good' cafes to try their espresso but they too taste like IMO similar to what I pulled.

So am I alone in this dilemma? I know it'll be length-ly discussion if I go into the details of the process, so I'll leave that out until later. Oh, my brew ratio is usually 30%. Should I take it higher?