Your morning coffee is becoming optional at Starbucks

Starbucks is quietly becoming an energy drink company as it rolls out an expanded "Refreshers" menu, with customizable caffeine levels. Beata Zawrzel/NurPhoto via Getty Images

Starbucks is pushing customizable caffeine beyond coffee with its new Energy Refreshers line.

The launch is part of a broader industry trend toward customizable functional beverages.

Starbucks reported strong Q2 earnings, signaling its strategy is building momentum.

Starbucks may be fueled by its coffee sales — but the company is increasingly catering to customers don't actually need coffee at all.

"We're seeing people that weren't energy drinkers in the morning become energy drinkers in the morning with our Refresher platform," CFO Cathy Smith said during Tuesday's second-quarter earnings call, pointing to a shift in how customers get their caffeine.

Starbucks launched its new Energy Refreshers platform earlier this month, offering three new varieties of its fruit-flavored…