A soft, rare fruit. Ambrosia tastes wonderful and produces a subtle mood-increasing chemical high. However, if eaten too often, it can generate a mild addiction.
Ambrosia is a raw drug (not a vegetarian food) that can be harvested from ambrosia bushes that only spawn in ambrosia sprout event (also available through trade), but cannot be grown by the player. It provides a +5 mood buff, +50% recreation and is slightly addictive. Ambrosia does spoil if not refrigerated. It also provides 0.2 nutrition.
It is harvested from ambrosia bushes. They can be harvested multiple times before dying, each time yielding 4 fruit when fully grown.
A good way to harvest them is to draw a growing zone over them, but forbid sowing. Colonists will then automatically harvest the bushes when they are fully grown.
The event can only occur, and thus the bush can only be found, in the following biomes:
Addiction to ambrosia is trivial compared to other drugs; it takes only 10 days before full recovery, and does not impair functioning; it only causes a -10 mood debuff as that pawn craves more ambrosia.
It is also somewhat rare to get an ambrosia addiction. The safe dose interval is 1.6 days. If used often, and ambrosia tolerance reaches 15% or more, then eating a fruit only has a 1% chance to create addiction.
Arguably, ambrosia is the best drug for early-to-mid games before food isn't a problem and beer, smokeleaf, and psychite tea is worth taking your farmers' time to farm. It provides a nice +5 mood buff, and addictions are no problem. Tell the non-addicted pawns to take 10 to their inventory, then box the rest into a small room. The mood debuff is negligible in the mid-to-late game. Each ambrosia sprout might provide 200-300 fruits, enough to last 5 pawns an entire year.