Lukas Sermann's family has been making wine in Germany's Ahr wine district for almost 300 years. On July 15, a night of flooding and ferocious storms all but wiped them out.

The rolling landscapes of the Ahr valley were among the worst hit by the disaster which killed at least 180 people.

A week on, most of the rescue work is done. Rebuilding businesses and lives is the next challenge - one that is testing the residents of this formerly prosperous corner of Germany to the limits.

"Morning is the moment when it all comes rushing back, and you remember everything that has happened in the last few days," said Sermann's partner Katja Pooch.

"And then you have to flip the switch and turn your emotions off and get on with it. We couldn't manage otherwise."

The floodwaters rushing through the cellar swept hundreds of bottles of wine away, flung wine barrels over, dented expensive stainless steel tanks, demolished walls and left the award-winning winery's surviving stock caked in mud.

A wine barrel is seen on the bank of Ahr river following heavy rainfalls, Germany, July 18, 2021.

Sermann and Pooch have spent the days since washing the bottles, hoping that at least some of them are still fit for market or to be auctioned off to help fund local relief efforts.

"We have undertaken some highly professional sensory testing," joked Sermann. "We just tasted some of the bottles. Here and there you can taste an off note. Most of the bottles were still OK."

But acts of generosity from competing winemakers elsewhere in Germany have given the family strength.

"It's just incredible, the help that we have been offered from other winemakers in the region, people saying they have a spare press, or tanks or pumps," said Sermann's father Elmar. "I think that with all this goodwill we will make it."