Zestar! is a early season apple that comes from the University of Minnesota breeding program (trademarked, USPP#11367). It is a good solid early apple, with a sweet-tart taste and a hint of brown sugar flavoring. The apple is medium in size, round, with red cover over 60-75% of the skin depending on sun exposure, and yellow undercolor. The flesh is white with a crisp texture, and while a nice texture for cooking the apple does tend to brown fairly quickly.
For an early season apple the taste is very good, and it also has a good shelf-life of a couple months. It is one of the parents of the new popular US variety, Sweetango.
Zestar! was developed for cold-hardiness, and performs best in cool climates. It is hardy down to zone 4.