When you make 25,000 G in Stardew Valley, Demetrius will come to your farm and offer you to convert your cave into something more useful. He’ll ask which one would you prefer: Mushrooms, or Bats.
This decision may be quite important, so I suggest you to think it over.
Fruits can appear in the cave even every day, so it is worth checking it at least every few days.
You can find there fruits like cherries, apples or berries. You can turn them into wine later, sell them, or use them as a gift.
If you choose mushrooms, 6 planters will appear in the cave, producing 6 mushrooms every two days.
These goods can be used, for example, to produce life elixir.
It’s your personal choice, but I went with Mushrooms.
It’s more consistent, and I know I should check the cave every two days. Fruits seem more accessible, so I don’t need to have more.