Searing Acidshock

The Searing Acidshock  is a fruit in Pikmin 3 and a treasure in. It is a green, unripened, also known as an ume. It takes three Pikmin to carry, and gives one bottle of juice (half a bottle in Ultra-Spicy mode). It also bears a slight resemblance to the Lesser Mock Bottom, although they're entirely different fruits. There are four Searing Acidshocks in Pikmin 3 Story Mode, appearing in the Tropical Wilds, Garden of Hope, and Twilight River, and three in Pikmin 4, in the Blossoming Arcadia, Hero's Hideaway, and Primordial Thicket.

Tropical Wilds
At the far end of the large body of water guarded by a Hermit Crawmad, there is a passage to another large area. A dirt wall must be destroyed, revealing a large, round area with a small chunk of land in the middle. Defeat the Puckering Blinnows in the surrounding water, and you will find a Calcified Crushblat on the chunk of land. Using nearby Candypop Buds, Rock Pikmin can be obtained to defeat the Crushblat, which has the Searing Acidshock. Use the Candypop Buds once again to transform the Rock Pikmin back into Blue Pikmin, and carry back the fruit. Alternatively, you can destroy the creature easily with three bomb rocks.

Crystal
After Louie has been saved from the Scornet Maestro, he will run away, destroying the cinder block in the Garden of Hope, opening up a new section. Blue Pikmin must be used to retrieve submerged fragments in order to build a bridge across to a tiled chunk of land. A Waddlepus will be found here, along with a Burgeoning Spiderwort and a large crystal which contains the Searing Acidshock. Upon destroying the crystal, the fruit will be ready to be taken back.

Bug-Eyed Crawmad
Another Searing Acidshock is found in the area beyond the cinder block, and is inside a Bug-Eyed Crawmad next to a large pile of fragments. The creature is surrounded by water on both sides, so Blue or Winged Pikmin must be used to fight it. Winged Pikmin make for a quicker fight, since they automatically fly up to the creature's eye-stalks without needing to throw.

Twilight River
Using lily pads, you must cross the river north of the landing site and head to the west until coming across a Puffy Blowhog. Close to the edge of the river in the area there are some Flukeweeds. One requires 3 Winged Pikmin to lift and holds the Searing Acidshock. Thanks to a branch nearby that leads directly back to the Drake, the return trip should be very quick for this fruit.

Blossoming Arcadia
There is a Searing Acidshock inside of a Waddlequaff at the eastern edge of the overworld. To collect this treasure, you must build the climbing wall on the western wall, located next to the sequence of jars, and then get it out of the Waddlequaff. To do so, either defeat the creature, or force it to spit it out with enough damage, then distract the enemy while the treasure is being carried off.

Hero's Hideaway
There is a Searing Acidshock hidden on the floor, inside some jars, near the northeastern corner of the kitchen floor. To collect it, you must break the jars, defeat the two Gildemandwees that appear, and then throw 3 Pikmin at it.

Primordial Thicket
There is a Searing Acidshock inside of a Baldy Long Legs near the south of the overworld, at the Autumnal Gully base. To collect this treasure, you must first defeat the Baldy Long Legs, then throw 3 Pikmin at it.

Trivia

 * Umes are often pickled, turning into the dish "umeboshi", or Japanese salt plums. They have a strong sour and salty taste. This is why Brittany suggests pickling the Searing Acidshock to make it more palatable.