A Jasper County couple say they are not guilty of manufacturing drugs. 43-year-old Stephen Welch and 41-year old Penni Welch entered that plea today in Jasper County Court. The two are charged in connection with one of the largest meth lab busts in county history. Last week, officers spent nearly 15 hours processing the scene and seizing what they believe are large amounts of acids and other chemicals necessary to produce meth. Investigators say these items were taken from a home just north of Joplin. Stephen Welch will be back in court on October 11th. Penni will reappear on October 18th.