(CBSSF) — Most wine tasting rooms have reopened in Napa and Sonoma counties following the wildfires this month in the two counties, a winery advocacy group said Friday.

Fewer than a dozen wineries were destroyed or heavily damaged in the fires and some operated despite the challenging conditions, officials with the Wine Institute said.

Institute officials said except where the fire was the fastest and strongest, the high amount of moisture in the vineyards kept them from burning.

Vineyards in Napa, Sonoma and Mendocino counties represent about 12 percent of wine grape production in California.

Institute officials said because of the heat in late August and early September 90 percent of the 2017 harvest in Napa and Sonoma counties was completed before the fires.

Neither smoke nor heat from the fires affected the fermenting of wine or the wine already bottled.

Institute officials said the grapes grown in the 2017 season are excellent and their optimistic the vintage will be as well.