When do you guys start the timer? I am a total coffee rookie and Ive just recently purchased a breville barista express and noticed most videos show people starting their timer when the first drop hits the cup. Recently I've seen people saying timer should start as soon as you press the button but apparently my machine has a 5 second pre infusion stage so not sure if that should be factored in? I have it pretty well dialed into a 25 second shot once the first drop hits. I do have a bit of sourness still though so wondering if maybe I should start the timer sooner and go a bit finer on my grind. What do you folks do, timer start at button press or timer start at first drop? If at button press do I subtract 5 seconds for pre infusion or nah?