noun
whiteness; white part
Refers to the white part or white color of something, often used in cooking or describing natural objects.
卵の白みを泡立てる。
Whip the egg white.
この魚の白みは透き通っている。
The white flesh of this fish is translucent.
白さ is an abstract noun meaning 'degree of whiteness', while 白み refers to the white part or white color of a specific thing.
Derived from 白 (しろ, 'white') + nominalizing suffix み, indicating a quality or state. The kanji 味 is ateji.