Make sure there is no residue from the package remaining on any grape, and that their surfaces are all clean and clear.
Toss any grapes with broken skins you come across.
Use a knife sharpener if the blade seems too dull to cut. Do not use a peeler for skinning larger fruits and vegetables, or you may end up taking too much flesh off the grape.
Be careful not to press your palm against the blade’s edge.
Use your thumb as a guide while you cut. Make sure the knife is only cutting into the skin, and not the flesh of the grape.
Make sure every grape is fully immersed in the water. If you are boiling a single grape at a time, use a spoon or tongs to lower the grape into the water, and hold it there until it is time to remove it.
Again, ensure every grape is fully immersed in the water.
The grape skin may come apart in pieces, or in one big piece.
