What is one key feature of Retsina's production process?

The addition of pine resin at a specific stage is a defining characteristic of Retsina's production process. This distinctive practice originates from ancient winemaking traditions in Greece and serves to impart a unique flavor profile to the wine. The resin, typically from pine trees, is added to the must during fermentation, which allows the resin's aromatic compounds to infuse the wine. This not only contributes to Retsina’s signature taste but also has historical roots, as the resin helped to seal clay amphorae used for storage and transportation in ancient times. Thus, the timing and method of incorporating the resin are critical to achieving the traditional character associated with Retsina.

Other options, while unrelated to Retsina's unique attributes, reflect different winemaking practices or styles. High sugar levels, high fermentation temperatures, and exclusive use of stainless steel tanks do not specifically align with the characteristic production of Retsina and do not contribute to its signature flavor profile.