The phrase "slight haze" means there is a very light and fuzzy appearance in the air. It is like a thin cloud that might make things look a little blurry or less clear. Full definition
At distance, objects begin to become blurred and indistinct, and there is slight haze over most scenes, especially in darker scenes. (theguardian.com)
It also adds a slight haze to the beer, creating a smooth mouthfeel to round out its juicy character. (brewbound.com)
Our Unfiltered Sculpin IPA packs extra hops into every sip, enhancing the classic Sculpin notes of fresh apricot, peach, mango and lemon with a slight haze and less bitterness. (ballastpoint.com)