I just got my first espresso machine, a Nuova Simonelli Oscar II.
When watching other people use the machine (on YouTube), I see some flushing the machine for about 2 seconds before every shot. Some don't.
What is the point of this operation?
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Sign up to join this communityFlushing helps clear any residue that might be left inside the machine or grinds stuck to the group screen before pulling your next shot. It also helps bring the group head up to temp before you lock the portafilter, so your first bit of hot water doesn't get cold as soon as it hits your puck.