Most store-bought brands, with the exception of Sach Foods paneer, will require you to soak the cheese in warm water to soften properly before use. If you skip the soaking, the paneer will still be edible, but it might have a chewier, tougher texture.
To soak your paneer, simply cut it up into 3/4-inch cubes and place it in a bowl in warm water for at least 15 minutes.
