The Starbucks Workers United hub in Buffalo on November 16, 2021.The Starbucks Workers United hub in Buffalo on November 16, 2021.

Three more Starbucks locations in the Buffalo, New York, area have voted in favor of unionizing, dealing yet another blow to the coffee giant as more of its workers organize.

The company-owned cafes in the Buffalo area, as well as one in Mesa, Arizona, have decided to form a union with the help of the Service Employees International Union. Only one location in the Buffalo area has voted against unionizing, giving the union a win rate of 85%.

The initial Buffalo victories for the union have galvanized other locations nationwide. In the last month, the number of stores filing petitions with the National Labor Relations Board for union elections has doubled. More than 100 Starbucks cafes have filed for union elections in the last six months.

It is a small portion of the company's footprint. Starbucks has nearly 9000 locations in the U.S.

The union's victories in Buffalo were close. The location in Anderson voted 15 to 12 in favor of a union, while the location in Walden voted eight to seven in favor of a union.

The regional director of the National Labor Relations Board will have to certify the ballots, which could take up to a week. The union will have to negotiate a contract with Starbucks. Labor laws don't require that the employer and union reach a collective bargaining agreement, and contract discussions can drag on for years.

After Starbucks workers in Buffalo won the first union for employees of a company-owned location, Starbucks head Rossann Williams wrote a letter to all U.S. baristas saying the company would bargain in good faith.