Modelled on sites such as match.com, the Cyros site lets you filter donors by everything from eye colour to blood type. Choose a donor and, depending on their anonymity preferences, you could even hear a recording of their voice or see photos of them as a baby. Crucially though, Danish law allows donors to keep their anonymity, unlike in the UK where, to donate, a man must agree to be identifiable in the future so any offspring can contact him when they turn 18.

Browsing through the site, I’m struck by the very personal nature of many donor profiles. Everything is listed, from their parents’ careers to frank appraisals of their own bad qualities – “I lose interest in tasks quickly,” writes one.

“There isn’t one single type of man that all women go for,” 30-year-old lab technician Mette tells me as she places vials of semen in a smoking box of liquid nitrogen. “But sporty types do sell well.” Given that it’s one of the biggest decisions a woman is likely to make, selecting a donor, whose profile image is a picture of themself as a baby not an adult, proves difficult for many customers.

“So many people sent in celebrity requests we’ve added a lookalike field on each profile”

“Sometimes they call asking for help choosing between their top three,” explains 30-year-old sales and customer services assistant Sandra. “And often they ask if their chosen donor is good looking. I can’t answer either really – it’s all so subjective.”

“Generally people want a better looking, smarter version of themselves,” explains Schou. “Heterosexual or lesbian couples often send in pictures of one partner and ask us to match a donor to that person. Single women have sent us pictures of their fathers or brothers, asking us to find a similar looking donor. So many people sent in celebrity requests – from models to Bruce Willis – that we’ve now included a celebrity lookalike field on each profile.”

“We want it to be as natural a process as possible,” he adds. “In nature, the woman chooses who she will have a child with and often it isn’t based on looks. It is based on an instinct. We want to offer enough information for that instinct to kick in.”

Yet, however warm the atmosphere, there’s no escaping that this is an artificial environment. To the left of the white-washed waiting area, there are three small rooms with lights above the doors that glow red when they are occupied. These are the donor cabins, where the men masturbate. Each has a tasteful nude photograph on the wall and a less tasteful rack of porn mags, as well as a video screen and selection of porn videos, a sink and a wipe-clean bed.

“The first time I donated was problematic,” explains 25-year-old butcher Henrik. He’s been visiting once a week for the past six months after seeing a sponsored link on Facebook. “It’s not like at home. I was in a hot room, getting sweaty. Plus there’s a mirror on the wall. I just couldn’t turn myself on and I had to really concentrate.”

Meet the man who's made 30,000 children