"It was delicious, very strong, very sweet," Andrew Chifari says.
"After the first day, the ice crystals had melted and it was just good strong iced coffee."
Chifari, 27, entered a Dallas Starbucks on May 24 with a 128-ounce glass and asked baristas to create the most expensive frappuccino that would fit in his container, but still taste good.
The drink cost $54.75, but Chifari walked away without paying a cent after racking up enough points under a loyalty plan for a free drink of his choice.
Starbucks does not want others to follow suit.
"This particular customisation was certainly excessive. It's something that we don't encourage," said spokeswoman Maggie Jantzen.
Starbucks did not say whether it would revise its free-drink policies in response to Chifari's order.
The coffee monstrosity is now recognised as the current record holder of the most expensive Starbucks drink by Caffeine Informer, an Internet site that keeps track of the coffee industry.
Caffeine Informer estimates the drink had 4500 mg of caffeine, more than 10 times above what the US Food and Drug Administration considers to be a maximum safe amount for a healthy person to drink on a daily basis.
Chifari consumed a third of the drink on the first day and polished off the rest in small intervals. The final caffeine surge on Wednesday caused him to have erratic sleep and vivid dreams.
"It was worth it. Overall, considering how much caffeine I consumed, I would have expected the sleep issue to be a lot worse than it was," he said.
