Before moving to France and then the United States, May-Britt had worked as a sommelier in many of Stockholm’s top restaurants. Eventually she started her own restaurant, La Bateau, on the Royal Star, a luxury yacht built in 1964 for King Frederic of Denmark. She received numerous distinctions as a sommelier, including the Prince Henri-Melchior de Polignac award in 1992. The contest was judged by Sotheby’s Master of Wine, and May-Britt was designated as the best sommelier in the Nordic countries.

In 1994, May-Britt had an opportunity to visit Bordeaux. When she finished a tasting with Francois Pinault, the owner of Chateau Latour, he asked her which wine was her favorite. She named the 1985 Château Lynch-Bages and and told him why; he appreciated her honesty and asked if she would consider working for him. May-Britt was ready for a change. She sold her restaurant business and within three months began overseeing public relations at Chateau Latour. There she met Denis Malbec, Château Latour’s cellar master and enologist.

In 2000, May-Britt and Denis moved to California where they established Malbec & Malbec, their own enological and viticulture consulting business to expand their vision of crafting exceptional wines from the world's most distinctive regions. Tragically, Denis died in an automobile accident in April 2016.

May-Britt is currently the winemaker and owner of Notre Vin, French for “Our Wine,” which is noted for its Howell Mountain Cabernet Sauvignon and Burgundian-style Sonoma Coast Pinot Noir, among other wines.