Final answer:
The two authorized grape varieties in the DOP Goumenissa are Xinomavro and Negoska.
Step-by-step explanation:
The two authorized grape varieties in the DOP Goumenissa are Xinomavro and Negoska. Xinomavro is a red grape variety widely grown in Greece and known for producing rich and complex red wines. Negoska is also a red grape variety commonly found in northern Greece and is often used in blends. These two grape varieties contribute to the unique characteristics and flavor profiles of the wines produced in the DOP Goumenissa region.