Wild Bunashimeji has bitterness, but Hokto mushroom is developed to weaken the bitterness. In rare occasion, some people still can taste the strong bitterness. However, the constituent of bitterness is Polyphenol, which is a beneficial nutrition.
Base is not edible, please remove them. See preparation tips for more details.
Individual mushrooms sometimes have different colors, some of them are whitish or blackish which does not affect quality.