What to Do Pour the vinegar and salt into the jar. Clean the nail with the baking soda and sponge. Wait fifteen minutes. What Happens The nail is coated with copper, and the pennies are shiny clean. The oldest way to make vinegar is to leave wine made from fruit juice in an open container, allowing microorganisms in the air to convert the ethyl alcohol to acetic acid.
Vinegar lasts indefinitely in the pantry without refrigeration.
Hannibal, the Carthaginian general, used vinegar to help clear boulders blocking the path of his elephants across the Alps. Titus Livius reported in The History of Rome that Hannibal's soldiers heated the rocks and applied vinegar to split them. According to the New Testament, Roman soldiers offered a sponge filled with vinegar to Jesus on the cross. While the act is considered cruel, vinegar actually shuts off the tastebuds, temporarily quenching thirst, suggesting that the Roman soldiers may have been acting out of kindness. Copper is the best low-cost conductor of electricity.