At 7:30 this morning, Starbucks Coffee comes to Harvard Square. For coffee-loving students, the new store's opening on Broadway across from the Sackler Museum--coupled with the mid-November opening of another branch on Mass. Ave. near the Quad--could change the Square forever.

At Au Bon Pain and other Square cafes, customers have to sort through sandwiches, chocolate chip cookies, soups and salads to get to the coffee menu. Indeed, only Coffee Connection has hitherto billed itself as a purveyor of the full-blown coffee culture.

Starbucks will change all that. It stands to become the new office of hip TFs, the new restaurant of sophisticated breakfasters, the new library of caffeine-addicted crammers.

You might not know it from the new store's employees, who were tight-lipped yesterday, except when they were sipping what was presumably a test batch of their product and referring all questions to their corporate office in Seattle. But the top brass will tell you that atmosphere and coffee quality are everything and that the new Starbucks will be the place to drink.

"There's more to it than just a cup of coffee," gushes Laura Moix, Starbucks media relations manager. She cites the hours of classroom training and "bar training" for all Starbucks employees in the preparation of everything from a double tall half-caff skinny latte to a grande americano with room.

(For the uneducated, the first is a medium-sized drink with one shot of espresso, one shot of decaf espresso and steamed and frothed skim milk, while the second is a large drink with espresso and hot water added, not quite full for the customer to add milk or cream.)

But if that means Coffee Connection is in trouble, no one is saying it, probably because Starbucks acquired the whole Coffee Connection chain last spring. They remain under separate management, although Passion for Coffee: A Starbucks Coffee Cookbook recently went on sale in Coffee Connection's flagship in the Square.

Officials at Starbucks headquarters say they aren't trying to steal Connection customers with the new store.

"It's going to be different," says Jennifer Tisdel, the Starbucks marketing director who spent time at local coffee establishments while working on a 1992 Harvard Business School degree. "The new Starbucks is newer. They'll play different music. The ambience will be different. I don't assess a value judgment to that at all."

Fans say the dark roast brings out the full flavor of the coffee; critics say it simply makes the brew taste burnt. The most cynical have taken to calling it "Charbucks."

Dark beans, light room--go to Starbucks. Light beans, dark room--try Coffee Connection.

"It's why someone drinks white wine instead of red wine," says Paul E. Twohig. Starbucks region operations manager for New England.

But perhaps the two establishments have more in common than one might think. Both feature a "coffee of the day." Both have retail counters for purchasing grinders, mugs, whole beans, espresso machines and a dazzling array of other accessories. Both serve up a wide array of coffee varieties and blends--a feature that allows customers to develop favorites and keeps them coming back for more.

Tisdel's favorite options at Starbucks, for example, are Guatemala Antigua ("rich, satisfying, and full of lively flavor complexities" says a brochure) and the Gold Coast Blend.

"[Gold Coast Blend's] got a carmelly sort of sweetness to it that some of the other coffees don't have," Tisdel says.

Therein lies the Starbucks mys- tique: There is a sense that what we once gulped down as a pick-me-up has become a metaphysical experience.

"It's not just a cup of coffee," Moix says. "It's whatever you want to be open to and willing to try."

Students and faculty seem likely to try it, if only because the new business provides variety and, in the case of the new Quad branch, a more convenient location for some students.

"Generally a Starbucks store is going to draw from the people that are already there," Twohig says. "It's still a neighborhood coffee shop.