Cody Gakpo threaded a ball through to Isak, who fired past Scherpen within six minutes.
The Swedish forward then bagged his second just three minutes later, once again found by Gakpo before slotting home with a left-footed finish
Two goals in eight minutes, and the game was effectively over as a contest before it had barely begun. Gakpo provided the assist for all three of Isak’s goals in the new season, with the second a lovely outside of the boot pass.
Bradley Barcola also came on for his Liverpool debut after his big-money arrival from PSG.
Isak thought he had his hat-trick before the break, finishing a lovely pass from Florian Wirtz, but was found to be marginally offside.
Ipswich showed promise in the final third but struggled to find the final bit of magic to carve a route back into the game.
They threw players forward in the second half in search of a consolation, but Alisson was rarely troubled.