Fulvio Bressan took to the Internet to rant against Integration Minister Cecile Kyenge, an Italian citizen born in what is now Democratic Republic of Congo.
Bressan called the minister a "dirty black monkey" and other racist epithets, later defending his comments by saying he was angry the government was planning to use taxpayer money to house illegal immigrants in hotels.
The organic winemaker, based in the Friuli Venezia Giulia region of northeast Italy, has been praised for the traditional techniques used at his family farm.
But Monica Larner, the Italian reviewer for the prestigious industry publication the Wine Advocate, said: "In light of the unacceptable comments recently made by Fulvio Bressan, I will not taste his wine."
Commenters on social media have called for a boycott and the global gourmet network Slow Food on Friday also said it was dropping him from its Slow Wine list.
Bressan's comments "are so harsh that they cross every line in sight," Slow Food said in a statement.
"Their haunting echo resounded nationally here in Italy as well in many countries abroad where his wines are sold," it said.
Bressan's rant was the latest in a slew of insults against Kyenge from anti-immigration advocates, including the deputy speaker of the Italian Senate Roberto Calderoli who compared her to an orangutan.