Its employees — there are 180,000 around the world — have reported that customers accuse them of “working for Nazis.” There have been boycott threats; this month, The Boston Globe published a scathing article with the headline: “I found out Nazi money is behind my favorite coffee. Should I keep drinking it?”

The outrage has flared without the public knowing the full extent of Mr. Reimann’s Nazi convictions — and without knowing the final wrenching twist: that the history of the Reimann family is one of both victim and perpetrator. The heirs carry both sides within them. In a series of interviews with The New York Times, members of the Reimann family spoke publicly for the first time about the Nazi scandal. They disclosed the story of Emilie Landecker’s Jewish father, Alfred, and described how his murder has forced the clan to reckon not just with the past, but with the future.

The Reimanns say they will spend some of their private fortune to honor Alfred Landecker’s memory. A one-time donation of 10 million euros (about $11.3 million) will go to institutions that help former forced laborers and their families. The Reimanns are also renaming their family foundation after him and doubling its budget to an annual €25 million, while ceding control of the board to an independent council. The foundation will fund projects that “honor the memory of the victims of the Holocaust and of Nazi terror,” and there are plans to fund at least one university chair in Germany in Mr. Landecker’s name.

A new website for the Alfred Landecker Foundation says its mission is to educate “about the Holocaust and the terrible price that is paid when intolerance and bigotry reign.” It continues, “The intention is to help strengthen our capacity to recognize the beginnings of such hatred and resist a repeat of such appalling events.”

In an interview, Mr. Harf noted that he lived in three places — New York, London and Milan — where nationalism and ethnic division were on the rise. For most of his long career, he said, he considered shareholder capitalism to be value neutral. No longer. In the age of Trump, Brexit and Matteo Salvini, he said, businesses can no longer pretend that they are operating in a “value-free space.”

“This is once again a time when everybody needs to take a stance,” Mr. Harf said. “I’m very scared of what’s happening.”

2. ‘A purely Aryan family business’

In July 1937, Albert Reimann Jr. wrote a letter to Heinrich Himmler, the leader of the SS, who would later oversee the Holocaust.