What Makes Lemons Such Good Cleaners?

A kitchen staple for their incredible versatility, lemons add brightness and acidity to sweet and savory dishes. They bring a hint of sunniness in the depths of winter, and on a hot summer day give us homemade lemonade, the perfect thirst-quencher.

But lemons are good for so much more. These citrus fruits are a natural cleaner, too. Here, we get a bit geeky about what makes them so useful.

As you probably know if you’ve ever bitten down into a lemon, these fruits are pretty sour. Chemically speaking, what your tongue interprets as sour is citric acid. Lemons are quite acidic — more acidic than orange juice and black coffee, although not quite as acidic as your stomach juices — and this is the key to their effectiveness as cleaning agents.

Although many types of soap are alkaline (i.e., not acidic), acids can be pretty useful when it comes to cleaning. They can eliminate stains caused by other acids, or combine with alkaline compounds to create powerful chemical reactions.

Let’s take a closer look at lemon’s cleaning powers.

Lots of things that stain clothes, including wine, coffee, lipstick, paint, and sweat, are acidic. Because like dissolves like, these stains need an acidic water-based solution. And the same principle holds for food-stained surfaces like cutting boards, plates, or bowls. Enter: lemons (and citric acid).

Lemon juice can also remove alkaline “stains” like limescale, that chalky white substance that often builds up on water fixtures or inside sinks and bathtubs, and rust. Here, the acidity of the lemon juice reacts with the limescale (calcium carbonate) or the rust (iron oxide) to soften and dissolve the deposits.

You may or may not already know that lemons are antibacterial. Their acidity creates a hostile environment for many kinds of bacteria, including those that cause salmonella and E. coli. It’s important to note, however, that lemon doesn’t have this effect on all pathogens, and also that it doesn’t kill them — it just makes them inactive.

Lemon’s acidity strikes again! Some types of bad smells (like from cooking fish or vegetables decaying in the garbage) are alkaline, so introducing acidity neutralizes the odors.

If the smell is coming from one place, like the garbage disposal, try dropping a cut-up lemon in there, then grind it up to make your sink lemony fresh. If the whole room reeks, try boiling lemon peels to get those fragrant acids to combat the stench in the air. Another tip? Rub a lemon on your fingers after handling garlic to prevent the pungent smell from lingering.

Are lemons part of your cleaning routine? How do you use them?