system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - Why do detergent pods dissolve in the water in the washing machine almost immediately, but don’t dissolve from the water present in the detergent they’ve been holding for months in the box?
gpt
The liquid in pods has a much lower percentage of water than regular detergent.  The shell does dissolve a little, but there is only so much that can dissolve in the tiny confined space before its saturated. The much larger amount of water in the wash can hold more dissolved shell so it softens the shell and washes it away.