Bongards Creameries, the co-op of Minnesota and North Dakota farmers that is one of the nation's biggest cheese producers, began construction this week on an addition to its Tennessee plant. It is also expanding its headquarters in Chanhassen.

Its Humboldt, Tenn., facility is getting a $35 million expansion that will double production, add 100 jobs and bolster its growing presence in the southeastern U.S.

Bongards also said it will complete a 12,000 square-foot expansion of its headquarters in Chanhassen by the end of this year. That includes a new test kitchen for customers visiting the headquarters to try experimental cheese products.

"I think this is very exciting," Keith Grove, the co-op's chief executive, said. "I'm finishing my 12th year here, and just to see where we were to where we we've grown to, is really exciting."Bongards does nearly $600 million in sales a year, and it has about 450 employees across four locations.

In addition to the Tennessee plant, Bongards makes cheese at facilities in the unincorporated town of Bongards, 40 miles southwest of Minneapolis, and in Perham, Minn., about 180 miles northwest of the Twin Cities.

Bongards two years ago completed a $45 million expansion to the Perham plant. Grove said the work on that facility increased the plant's output by 70 percent.

Over the past five years, Bongards has doubled its processed cheese sales. Grove attributed the rapid growth to increased marketing efforts, the expansion of the Perham facility and its expansion into the southeast. The farmer-owned co-op was founded in 1908.