Long ago I happened upon this page where someone took the time to invesigate the effects of various taco sauces on pennies. Since then, I’ve often thought about the effects of other hot sauces on pennies - would the type of vinegar have any differential effect, would the heat level of the hot sauce have any effect and which hot sauce would work best?

So I gathered up quite a few pennies, some shiney and brand new, others dulled by copper oxide (the reaction of the copper and the oxygen in the air).

Pennies get dull over time because the copper in the pennies slowly reacts with air to form copper oxide. Pure copper metal is bright and shiny, but the oxide is dull and greenish. When you place the pennies in the salt and vinegar solution, the acetic acid from the vinegar dissolves the copper oxide, leaving behind shiny clean pennies. The copper from the copper oxide stays in the liquid. Source: About.com

Goal of this experiment: To determine which of the following 4 hot sauces cleans a penny the best.
Prediction: Original Tabasco (because of the greater vinegar & salt content.)

A penny will be suspended in each hot sauce and then compared to an already shiny penny and a completely dull penny (for visual effect)

Sauce #1: Original Tabasco Hot Sauce

Ingredients: Fully aged red peppers, Avery Island salt and distilled high-grain natural vinegar.

Sauce #2: Tabasco Chipotle Hot Sauce

Ingredients: Chipotle pepper, distilled vinegar, water, salt, sugar, onion powder, spices, natural flavor, Tabasco brand pepper pulp (distilled vinegar, rad pepper and salt)

Sauce #3: Dave’s Cool Cayenne

Ingredients: Water, red chiles, salt, cane vinegar, xanthan gum, onions and garlic.

Sauce #4: Blair’s Jersey Death

Ingredients: Red Habanero Pods, Cayenne Chiles, White Vinegar, Natural Pepper Flavor, Tomato Puree, Pirri-Pirri Chiles, Pumpkin Seed, Lime Juice, Salt, Spices.

The Results

Surprisingly, Blair’s Jersey Death had little to no effect on the penny. Chipotle Tabasco appears to have cleaned the penny better then Original Tabasco - which is surprising given the taste of Original v. Chipotle - but looking at the ingredient list on each and distilled vinegar is higher on the ingredient list in the Chipotle Tabasco. So there you have it: Cleaning pennies with hot sauce does work, but you may as well save your sauce and use a plain vinegar and salt solution. Just be sure to rinse your pennies after removing from the solution, otherwise the solution will promote the oxidation between the copper and oxygen and will create a blue green copper oxide on your freshly cleaned pennies.