At Vantage Hemp’s huge factory in Colorado, cannabis goes through the complex process of being processed into CBD. Cannabidiol, or CBD, as it's better known, was once only a concern of the most tiresome of stoners. Now you can find it in tampons, face creams, ice creams, hummus, water, and at Tesco. It's a multibillion-dollar industry: the UK's CBD market alone has been forecast to reach $1.2 billion by 2025. This explosion in popularity can…