The wildfires sweeping across south Australia have destroyed vineyards supplying two of the country's biggest wine producers.

Constellation Australia, which makes household brands such as Hardys and Banrock Station, has company-owned and contract vineyards in the Yarra Valley area of Victoria, where the fires have been most savage.

Sheralee Davies, group PR manager for Constellation Australia, confirmed that while its personnel were safe and accounted for, concerns were mounting about the damage done to vineyards.

"We do have a presence in an area directly threatened by the fires, with our Yarra Burn brand sourced in the Yarra Valley," said Davies. "All of our personnel in the Yarra and Victoria are unharmed, but the fires are not all contained at this time. As things currently stand, our three company-owned vineyards have not been burnt, although some of our contract vineyards have been, and smoke taint will be a major issue across the entire region."

Changing winds were still complicating the situation as The Grocer went to press, and Davies said the company-owned vineyards were "still at risk of direct fire damage".

Foster's EMEA, which supplies the UK with Wolf Blass, Lindemans and Rosemount brands, said it was still assessing the damage in the Yarra Valley, where it also has company-owned and contract vineyards. "We have not been able to get into all regions because of the continued fire threat," said Anna Calver, senior PR and communications manager. "In the Yarra Valley we have lost one company vineyard of approximately 30 hectares and we lost approximately 10 hectares of vines at another company vineyard. Both vineyards had plantings of Pinot Noir, Shiraz and Merlot."

Jacob's Creek, the biggest brand in the Pernod Ricard house, was not affected directly by the fires as its vineyards are in a different part of Australia, but wine development director Adrian Atkinson said it was monitoring the situation.

"We have many friends and ex-colleagues who are affected by the horrendous fires," he added.