If one does not actually have this skill, the expression loses much of its explosiveness.
One rainy day, my sister left her daughter with our mother. Mama put a raincoat and rubber boots on her grand-daughter, grabbed an umbrella from the back hall, and outside they went.
My sister returned to find the two standing over a puddle letting spit balls fall on to its surface.
“Nice try. Try to ball it up in your mouth before letting it drop….Ready? Good! Now let’s count how many ripples are made! Ready? One, two….”
Mama looked up at her disapproving daughter. Mama tsk-ed her disbelief.
“All your fancy pre-school education classes and this child has not been taught to spit! Bah.”
Today, my niece is so sweet-natured that she rarely gets annoyed, but when she does, she says, “I am so mad I could spit!”
Watch out, because she can.