A Gift from the Potion Shop
On your first visit to the Potion Shop, speak with the shop’s owner. After explaining that you need a bottle to keep potions, she’ll give you one empty bottle for free!
Sealed Grounds Revitalizing Potion
After you speak to the Old Woman in the Sealed Grounds, find the treasure chest on the right side of the room. Inside, you’ll find a bottle of Revitalizing Potion.
You will receive a bottle of Fungal Spores during the “Injured Loftwing” sidequest. After you have delivered the spores, you can keep and reuse the empty bottle.
There is an empty bottle hidden in the Fire Sanctuary.
There is an empty bottle found inside a Goddess Cube chest.