Joja Cola

It feeds you, which is fine and forgettable. The reason to keep one is the Dryad. Hold a cola while you talk to her and her usual status line is replaced with an option to purify. Take it and a Junimo pops out of a portal, hauls a Stardrop out of the ground and leaves it behind before disappearing. Nothing limits how often you can do this, so every cola you fish up converts into one.

You do not craft or buy these. They come up on the line while fishing, in place of the usual junk. That makes any fishing session a slow trickle of them, and worth doing before you go and pester the Dryad.

Both the drink and its role as fishing garbage are lifted straight from Stardew Valley. Having to hold the item in hand before the Dryad reacts copies how you hand things to people in that game.