(KTLA/NEXSTAR) — Summer’s still blazing across the U.S., but it’s officially fall at Starbucks. The coffee giant’s Pumpkin Spice Latte is available at locations nationwide starting Tuesday — one of its earliest-ever release dates.

But even though the “PSL” has become a cult classic, the seasonal favorite wasn’t always beloved.

The drink was not a huge hit with taste-testers when it was proposed in 2003, Starbucks veteran Tim Kern told Quartz in 2013. The reason for some of the skepticism was part of why it would ultimately become so popular: the flavor.

“A number of us thought it was a beverage so dominated by a flavor other than coffee that it didn’t put Starbucks’ coffee in the best light,” Kern said.

Then-Starbucks product manager Peter Dukes — who’s considered “the father of the pumpkin spice latte” — says tasters’ concerns almost kept the drink from seeing the light of day. Dukes, who admits that PSL wasn’t a favorite among other new flavors being considered at that time, has frequently opined that the Pumpkin Spice Latte was “the flavor that almost wasn’t.”

Starbucks ultimately decided to test the drink in 100 stores, according to Food & Wine. The gamble paid off big.

“Within the first week of the market test, we knew we had a winner,” Dukes said in 2014. “Back then, we would call store managers on the phone to see how a new beverage was doing, and you could hear the excitement in their voices.”

Forbes estimated Starbucks sold 200 million PSLs by 2010 and made about $100 million on them by 2015.

The beverage combines Starbucks’ espresso and steamed milk with flavors of cinnamon, nutmeg and clove. Real pumpkin is also incorporated into the recipe, according to the coffee giant.

The drink is available hot, iced or blended.

Why is the Pumpkin Spice Latte so popular?

In 2016, A. Pawlowski, a writer for TODAY.com, tried to dissect the drink’s popularity. Pawlowski talked to NBC News’ Health and Nutrition Editor Madelyn Fernstrom, who offered three possible theories:

  • The drink’s combination of fat and sugar, in addition to its cinnamon, nutmeg and cloves, are “a treat for the taste buds.” Salt content was also noted, as Fernstrom indicates that the PSL contains “one-tenth the amount of salt you should be consuming in a whole day.”
  • The second possible reason for its popularity is brain association. According to Fernstrom, the spices you associate with fall — nutmeg, cinnamon and cloves — bring happy holiday memories to mind and make you feel happier.
  • Third, and most obviously, caffeine.

In addition to the PSL, the Pumpkin Cream Cold Brew is returning for its fourth year on menus. It combines Starbucks cold brew with vanilla syrup, and it is topped with pumpkin cream cold foam and a dusting of pumpkin spice.

While August 30 is among the earliest release dates for Pumpkin Spice Lattes, it isn’t the earliest in recent history: The drink returned to stores on August 24 last year.