Final answer:
The DOP Goumenissa authorization covers Xinomavro and Negoska grape varieties, which are used to make rich and complex red wines in northern Greece.
Step-by-step explanation:
The two authorised grape varieties in the DOP Goumenissa are Xinomavro and Negoska. The DOP Goumenissa is a protected designation of origin for wines that come from the Goumenissa region in northern Greece, close to the city of Thessaloniki. This area is known for producing red wines that are rich in flavor and complexity. Xinomavro is the primary grape variety in the region, often associated with wines that have robust tannins and a good aging potential due to its high acidity and strong flavor profiles. Negoska, on the other hand, contributes to the wine's unique character, adding a softer, fruitier element that balances the final blend.