A rendering of the 43,000-square-foot Starbucks Reserve Roastery opening in 2019 at Michigan and Erie streets. View Full Caption Courtesy of Mayor's Press Office

DOWNTOWN — At four stories tall and 43,000 square feet, the largest Starbucks in the world is opening on the Mag Mile, Mayor Rahm Emanuel announced Wednesday.

The Starbucks Reserve Roastery will open in 2019 at 646 N. Michigan Ave., currently the home of Crate & Barrel's flagship store.

"The interactive space will be designed to bring coffee craft to life by offering multiple brewing methods, specialty Reserve beverages and mixology," Emanuel said in an announcement.

Chicago has no shortage of Starbucks Downtown and, about 30 years ago, was the first city to open a Starbucks outside of Seattle. The Mag Mile roastery will be the third, and biggest, for Starbucks.

“Chicago’s Magnificent Mile brings in millions of visitors from across this globe and is the perfect location for a world-class coffee destination,” Emanuel said.

He called the project “an investment in Chicago and a strong addition to Michigan Avenue."

The Crate & Barrel store will close in early 2018, a spokeswoman told the Tribune.

Howard Schultz, Starbucks executive chairman, said because of Chicago's place in the company's history “this is a very special city for me."

Schultz recalled that at the time of the opening of the first shop outside of Seattle "it was a true test for Starbucks because the Chicago customer is so savvy and discerning about their coffee.”

“Chicago is a city of neighborhoods, so we took our time to find an incredible space to match the unprecedented coffee experience our premium Roastery will offer," Schultz said of the Michigan Avenue location.

"To be located on one of the best-known retail streets in the world is a proud moment for all of us and we can’t wait to bring Chicago and the world a coffee experience worthy of their most premier real estate,” Schultz said in a prepared statement.

The owner of the Michigan Avenue building is Gordon Segal, who founded Crate & Barrel but has since sold the retailer.

"This building has a unique way of becoming a beacon for a brand, and I can't think of a better retailer than Starbucks," Segal said.