I've always loved good gin, especially in a dry martini, but around 2000 I'd started to find it harder to find a true London gin. I was working in Tokyo as a banking specialist, and I would often wind down over a martini. One night, I began lamenting to the bartender about the loss of old-style gins. To my surprise he agreed, and gave me a taste from a 1960s bottle and one from 2000. What I found were two very different spirits.

A few years later – after a few more tastings of vintage gins the bartender had managed to source – it was time for me to come back to London. The bartender gave me one of these bottles as a parting gift and said, jokingly, "You should make some of your own gin." This got me thinking. Research led me onto Charles Maxwell, a master distiller at Thames Distillery. I met him, and I told him I wanted to create a gin. He said I was mad, and that I should be making vodka as that was the more popular drink at the time. I manage to convince him that I wanted to create gin "as it should be" and so we set about creating a London Dry gin resembling the old-style gins I'd tasted. Over a year of trial and error, and I got the result I wanted: a classic, smooth gin, perfect for a martini.

Then, even more curious about gin, further research led me to a distiller's handbook from the 1800s and within it a recipe for another lost style of gin – Old Tom. So we started producing this as well.

I wanted the gin to be distilled by me under the Jensen's name, so I commissioned a still with John Dore & Co. It now sits under our archway in Bermondsey, where we've distilled ever since. I'm still involved in the banking sector but my real passion lies with producing and drinking the perfect martini.