Henriette Waal and Sander Nederveen Showing the Participants how the Juicer Works Share Facebook Twitter LinkedIn Pinterest E-mail During the gastronomical summit there were several workshops you could participate in. One of them was making knotweed juice in the workshop "Knot Your Average Juice" with Henriette Waal & Sander Nederveen. Photo by Jada Maij With: Henriette Waal, Sander Nederveen Where was this made?: Gastronomical Summit