This is copied from the pikipedia. I cannot rewrite this due to my laziness. Sorry!
Ultra-spicy spray is a red-colored spray that can be obtained by gathering ten Ultra-spicy berries from a Burgeoning Spiderwort plant, or finding a concentrated dose. The first time one of these berries is found, the ship gives a short speech and then requests the two captains to bring it another specimen. After the ship receives nine more berries, it will create an Ultra-spicy spray. This spray is usually discovered before the Ultra-bitter spray.
Obtaining the spray
Concentrated doses can be found by breaking eggs, defeating petrified enemies, fighting Iridescent Glint Beetles and Iridescent Flint Beetles, squishing the insects at the Wistful Wild, or defeating red Unmarked Spectralids. Red berry-producing Burgeoning Spiderworts are located in every above ground region except the Valley of Repose.
Unleashing this spray on a Pikmin replaces its leaf, bud or flower with a red flashing light, similar to the one over Olimar's head. Their maximum speed becomes almost as fast as flowered White Pikmin and the affected Pikmin gain attack speed, which also improves their efficiency when deconstructing gates, constructing bridges and recovering from enemy attacks. After 40 seconds, all effects wear off. While the spray's effect can be extremely useful in many situations, caution should be observed, as drowning, burning or suffocating Pikmin sprayed with an Ultra-spicy spray will actually die more quickly than unsprayed Pikmin.
Although the spray causes most of the Pikmin to improve in terms of speed and attack, all changed attributes are set to the same value for all colors, meaning that flowered White Pikmin lose some speed and Purple and Red Pikmin lose attack strength; all Pikmin experience a gain in attack speed, however.