It's true — soap and detergent aren't the same. They're made with different processes and do different things. Soap is created with a process called saponification, while detergent is a mix of chemicals that use one or more mechanisms to grab dirt and rinse away without any residue. Here are a few more interesting facts that might make your life a little cleaner:
* Soap (the saponified kind) can't clean your clothes (or rinse away) as well as store-bought laundry detergent, but can ruin your clothes and wreck your washing machine. Most homemade laundry soap contains bar soap, and is best avoided.
* Most commercially sold detergents will also sanitize your laundry — no bleach required.
* You're probably using too much laundry detergent, especially if you have a high-efficiency washer. Most detergents are so concentrated that two tablespoons are sufficient for a large load, regardless of what the label says.
* The world's first commercial laundry detergent was Persil, introduced in 1907 by the German firm Henkel. The name is shorthand for perborate and silicate, two of the product's main ingredients.
* Before the invention of modern synthetic detergent, people relied mostly on muscle to clean their clothes — slapping and twisting them against paddles, washboards, and river rocks. People also used soap, animal fat, and lye as cleaning agents, or occasionally something called "chamber lye" — an awkward euphemism for urine.
* Automatic electric washing machines first appeared in the early 20th century. The Thor, introduced in 1908, featured a galvanized tub, an electric motor, a clutch, and an emergency stop rod.
* Yellow armpit stains aren't from sweat — they appear when the minerals in your sweat mix with the ingredients in your antiperspirant. To remove armpit stains from white shirts, soak the stain in equal parts water and hydrogen peroxide.
