Powder Keg Shop
You need to rewind time in order to fully take advantage of the mountain’s thaw, but there’s one more thing worth doing before you do so. Soar to Mountain Village, and make your way east into Goron Village. Drop to Goron Village’s lower area, and go north to locate a large cave. The sign out front reads “Goron Powder Keg Shop.” Sounds intriguing.
Enter the Goron Powder Keg Shop, put on the Goron Mask, and then speak with the big Goron that runs the place. Due to the Powder Keg’s explosive might, all new customers are required to pass a test before they can buy Powder Kegs. Accept the Goron’s challenge, and he’ll ask you to use a Powder Keg to destroy a boulder that blocks the entrance to the Goron Racetrack.
The Powder Keg’s fuse is already lit, so you’d better hurry. Press 
to pick up the Powder Keg, then approach the series of ramps that you descended on your way into the shop. Press 
while moving forward to throw the Powder Keg over the first ramp, then roll up the ramp. Pick up the keg again, toss it up the next ramp, and then roll up again. Keep going until you exit the shop.
Once you’re out of the shop, run forward a bit, and then go up the winding ramp with the railing on your right (west). Carry your Powder Keg west, returning to the Road to Goron Village.