What is the primary characteristic of Junmai Ginjo-shu?

The primary characteristic of Junmai Ginjo-shu is that it is made from rice that has been milled to at least 60% of its original size. This milling process is crucial in defining the quality and flavor profile of the sake. By removing the outer layers of the rice grain, which can contain fats and proteins that may lead to off-flavors, the resulting sake can achieve a more refined taste with a smoother and fruitier profile.

Junmai Ginjo-shu specifically refers to a type of Junmai sake that not only has reduced rice milling but is also brewed without any added distilled alcohol. This differentiates it from other sake types that might have added alcohol to enhance flavor or aroma. The focus on utilizing highly polished rice is what sets this category apart, emphasizing purity and expressiveness of the rice itself.

In relation to the other options, while they refer to different aspects of brewing or sake categorization, they do not define the essential characteristic of Junmai Ginjo-shu specifically. The process and ingredients might vary with different types of sake, but the milling requirement for Junmai Ginjo-shu is what fundamentally distinguishes it.