Plath, the son of Morgenrot founder Rudi, started working for the company in 1997 after completing his finance and accounting degree. He was appointed acting MD in March.
He said: “It’s a real honour to be made MD and I am excited to have the opportunity to carry on the work of two great men who have taught me so much - my father and Ray Flynn.
“It has been a difficult last few months but I am very proud of the way our team has pulled together and with their continued hard work and dedication, I am confident that as a company we will continue to grow and gain strength.”