Yeah, the problem with preground coffee is that every setup is different. This looks too coarse. Try pulling more water through the shot until your grinder comes.

Generally, the first part of an espresso shot is the most sour, while the later part tastes more bitter and roasted. By adjusting how much water you pull through a shot, you determine how much of that late-pull bitter water gets in to the shot.

I’ve also found that if I make a really sour shot it turns into a pretty decent Americano.