Her main challenge was mass producing her flavoured water without adding preservatives or sweeteners. “Frankly, we had no idea, because the industry didn’t have any idea how to develop a product without using preservatives.”

She researched how fruit juice is pasteurised to extend its shelf life, and went on to devise a similar technique for her waters, with the help of her husband Theo, a former patents attorney who is now Hint’s chief operational officer.

“We were the first fruit water brand to use a pasteurisation product to create our drinks without any kind of preservatives in them,” she says.

But while Kara had successfully worked out now to produce her drink on scale, she realised that she didn’t have any experience of running such a company. So she approached one of the global drinks giants to see if it would like to buy her start-up business.

She managed to get a phone conversation with a senior executive at the multinational in question, but as she revealed to Forbes magazine back in 2015, the talk did not go very well., external Kara says that the man called her “sweetie”, and that this sexism gave her the drive to continue to run Hint herself, and make a success of it.

Her next challenge was how to break into a market dominated by the likes of Coca-Cola and Pepsi, who both own their own water brands and a host of other soft drinks. “We had no idea of the power of the large soda companies,” she says.

Kara’s first step was to persuade her local branch of upmarket supermarket chain Whole Foods to stock Hint. She dropped off a few cases at the shop just hours before she gave birth to her fourth child. They sold out overnight.