"Shinshu" - the first sake brewed from that year's rice.
Generally, "new sake" refers to sake brewed with new rice harvested in the autumn of that year, known as "shinmai shinshu" (new rice new sake), or sake brewed in the cold of winter, known as "kan-zukuri shinshu" (cold-brewed new sake). These are shipped from winter to spring.
It is sometimes also called "hatsushibori" (first pressing).
It is sometimes also called "hatsushibori" (first pressing).