Did I underpitch?

[brazilhead]

I got a larger fermenter that holds 7.5 gallons and for my first larger AG batch I pitched one packet of US-56 (directions say it´s good up to 7.5 gallons) with no starter. It was a Pale Ale with an OG of 1.058. After 7 days there was still lots of krausen and because I need the beer to be conditioned by the 17th, I decided to do a primary-only fermentation. Even on the 16th day when I bottled there were traces of krausen though gravity was 1.012. It appears this beer will have quite a bit of sediment in the bottle. So, would 2 packets of yeast or another yeast have made a difference? Should I have done a starter? (Again, directions say it´s not necessary so I never have.) This is my first beer where I couldn´t transfer to secondary after a week. Your help is appreciated.

[Mill Rat]

Homebrewers are notorious underpitchers. RDWAHAHB. With dry yeast, a starter isn't usually necessary, but rehydration is helpful. Since I don't use dry yeast unless my liquid yeast has failed to launch, I can't speak to this authoritatively (has that ever stopped anyone, though?), but a second package would not have hurt you brew nor broken the budget.