With the rise of environment-friendly products on the market, vinegar has emerged as a folk hero of sorts when it comes to cleaning agents. There is a surplus of books, websites, and advice columns about the wonders of this ordinary household item. Testimonials and how-to's can be important, but they don't explore the science and interactions behind vinegar.
Vinegar is usually a mixture of between 4-5 percent of a chemical called acetic acid in water. This acid is versatile and can mix with water, oil, alcohol and almost any other kind of liquid, even gasoline, reaching places that other cleaning products can't. When it is dissolved in water, acetic acid breaks apart into two components, the hydrogen and the remainder of the molecule, called the acetate. The hydrogen will try to bond to any molecule that it encounters, acting like a third wheel and weakening the molecule's structure. These hydrogens are great at cleaning stains made from alkali substances, like soap, urine, and limestone.
The acetate component has an extra electron that hangs off the molecule. The electron acts as a magnet to other atoms, especially metals, to make new molecules. For example, the acetate reacts with molecules in rust and grime and changes their makeup so the water can dissolve them. Acetic acid also gets rid of odors by killing off the bacteria and fungi that cause them. Its acidic nature destroys the cell structure of bacteria, and it stops fungi from turning sugar into energy.
Unlike strong chemicals, like hydrochloric acid, which get their strength by completely breaking apart in water, vinegar maintains a balance within water of about 1% separated acetic acid. This makes vinegar safe to use on cleaning surfaces, but makes it less effective fighting grease or carbon (char) buildup on cooking utensils.
There are a few things that you should not mix vinegar with. Firstly, alkali-cleaning products like soap, lye, and bleach will neutralize the vinegar and alkali at the same time and make both of them ineffective. (Not to mention creating poisonous fumes, as with bleach.) Sometimes, however, neutralization is important. To unclog a drain, you can mix vinegar and baking soda for the "volcano effect". The two will combine to create water and carbon dioxide, increasing the pressure in the drainpipe and dislodging some of the clogging material. Mixing vinegar with an alcohol and a strong acid will create a reaction and completely change the vinegar and alcohol. Lastly, do not try to boil vinegar or heat it up. At high temperatures concentrated acetic acid will become corrosive and can burn through metal and rock.
Vinegar shouldn't be used to clean upholstery, serious drain clogs or ovens. With upholstery, the acetic acid could cause a stain. Vinegar should also not be used to treat metals like iron, stainless steel, bronze, or copper. Following these guidelines and understanding the properties of vinegar can help you get the most from this alternative cleaning agent.