A microscope shows us that black pepper isn't really black. The berries are picked from the vine when they're green and then allowed to sit in the sun for a while. A black fungus called Glomerella cingulata grows on the skins. That's the only part that's black, the fungus. Green pepper is made by skipping the fungus-growing part.
White pepper starts off as green pepper, but then the green skin is rubbed off.
Shake black pepper onto the water until the whole surface is covered with floating pepper. Just touch the water with the toothpick. Be very gentle and still. Try not to disturb the pepper with the toothpick. Do the same thing with the corner of a bar of soap.