Stardew Valley farm cave: fruit bats or mushrooms?

When does Demetrius offer the cave?

Reach 25,000g in total earnings, then look for Demetrius at the farm in the morning. The number is your lifetime earnings on the farm. Spending gold on seed or tools does not lower that total. Read the two options when he visits and decide which part of your farm needs help.

The cave is near the northern edge of the farm. Fruit bats leave fruit on its floor. The mushroom setup puts six growing boxes in the cave and, on 1.6, includes a Dehydrator. There is no in-game switch for the unmodded save after choosing.

Which farm cave should I pick in 1.6?

Your next goal	Consider	What to plan around
Fill fruit slots in standard bundles	Fruit bats	Check the floor regularly. Drops vary, so reserve the right fruit when it appears
Use a Dehydrator early	Mushrooms	The setup includes a free machine and six boxes. The boxes produce every second day in 1.6
Build around fruit trees already growing	Mushrooms	Use the trees for planned fruit and the cave for mushrooms
Want mushrooms eventually but need fruit now	Fruit bats	A Mushroom Log offers another source in 1.6

Choose based on the item you would otherwise have to wait for. A cave that occasionally gives the fruit your bundle needs can save a planting season. If you already have the trees you need, a steady chance at mushrooms and an early machine may help sooner.

Fruit stays on the cave floor until you pick it up. If you need more fruit for a bundle, collect the existing drops and keep the floor open so new fruit has room to appear. With the mushroom option, plan a collection stop around the every-other-day production cycle.

A bundle example you can check

Suppose the standard Fodder Bundle still needs all three Apples. An Apple from the bat cave reduces that gap to two. Set it aside before selling fruit or using a separate Apple in the Artisan Bundle. Do the same with the Pomegranate for the Enchanter’s Bundle. Bat drops are variable, so plant a tree in time for its season if you need a reliable source for a deadline.

If you picked mushrooms, watch for the Purple Mushroom used in the Field Research Bundle. Put it aside before deciding which mushrooms to process. The Community Center seasonal checklist shows the other donations to save while you wait.

Can I change the cave after picking?

The unmodded game keeps your choice. You can still solve the need that made the other cave attractive. If you chose mushrooms and need fruit, plan your fruit trees and keep the first matching harvest for the bundle. If you chose bats and want mushrooms, work toward the 1.6 Mushroom Log and choose a spot near suitable trees. Keep checking the bat cave even after putting a different source in place.

For the next decisions on an early farm, use the first spring route and check when your next planting will mature with the crop planner.