The smell of lemon is the smell of cleanliness. There’s nothing like the scent of a freshly cleaned bathroom (lemon), a stack of spotless dishes (lemon), or a floor so pristine that five-second rules easily become three-minute rules (yes, again, lemon).
It’s marketing, for sure, but there’s also a reason for it. Lemons and other citrus fruits contain citric acid, and this natural compound also happens to be a great cleaning agent. You can make your home smell like a citrusy paradise with lemon-scented cleaning products, but you can also get cheap citric acid for cleaning assistance in some of the most problematic corners of your home.
You won’t actually get that signature aroma—citric acid in its pure, crystalline form is odorless. But who cares about that when you can actually see through your glass shower door for the first time in years?
(Also, please don’t eat off the floor—no matter how clean it looks or how lemony it smells.)
Why citric acid is good for cleaning
Citric acid has become a staple in household products mainly because of its disinfectant and chelation properties, which make it really effective against hard water.
“Chelation means that the molecule binds very strongly to metal ions. Since hard-water scales and rust have metal components, binding the metals breaks up the materials and makes them dissolve in the water,” explains Patrick Holland, professor of chemistry at Yale University.
[Related: A bare minimum guide to spring cleaning]
Just as in chelation therapy—which doctors use to eliminate heavy metals from the bloodstream in patients suffering from heavy metal poisoning—citric acid binds to calcium and lime, which are abundant in hard water. This allows other cleaning agents and surfactants to work better, and if you use the white crystals in higher concentrations, you can actually eliminate solid mineral deposits in your appliances.
How to use citric acid to clean a dishwasher
Hard water can do a number on your dishwasher—mineral residue can build up in the guts of the machine, and even clog them. So on top of running sanitizing cycles, you should do a regular deep clean with citric acid. This won’t just take care of any lime or metals ruining your dishwasher from the inside out: Citric acid is also known for being a great disinfectant, and it’s often suggested as a milder, more natural alternative to bleach, so it’ll also help with any unpleasant smells.
Dishwasher manufacturer General Electric recommends crystallized citric acid for cleaning the interior of dishwashers—also known as sour salts. Put 3 to 4 tablespoons of the compound in the detergent cup, close it, and run a normal cycle without any dishes. After that, GE suggests following up with another cycle (this time with regular dishwasher detergent).
How to use citric acid to clean an electric kettle
If you’re a fan of tea, you probably have an electric kettle, and it probably has some mineral buildup inside. Using filtered water instead of tap helps prevent this (or at least slow the process down), but if you have a hard water source in your area, it’s highly likely metals and minerals coming straight from your faucet have created a white crust. This residue can even crack and end up in your tea. Gross.
But because of its chelating faculties, using citric acid to clean your electric kettle is both fast and simple. Mix a tablespoon of citric acid with a liter (4 ⅓ cups) of water, and stir until dissolved. Boil the mixture and then let it sit for 15 minutes. After that, dispose of the solution, rinse the inside of your electric kettle, and stand in awe of your brand-new-looking appliance.
Rinsing after cleaning is important, but you shouldn’t worry too much about a smidge of leftover residue. Citric acid is widely used in the food industry, and it’s not only present in all kinds of fruit (including strawberries and pineapple), but also in jams as a preservative, and even in fizzy candy.
“A little bit [of citric acid] ingested wouldn’t hurt anyone,” says Holland.
How to use citric acid to clean showerheads and faucet aerators
I don’t think I’m exaggerating when I say that low water pressure can be counted as one of the horsemen of the apocalypse. Having just a single thread of water to clean yourself (or that pan with burnt lasagna ends stuck on the sides) cannot be defined as anything but a nightmare.
Low water pressure depends on a lot of factors—some of which are out of your control—but one you can definitely do something about is clogged showerheads and faucet aerators (the same thing, but in your kitchen sink).
The cleaning method is similar to that of the electric kettle. Just unscrew your showerhead or aerator (or both, if you want to multitask), and submerge it in a solution of 1 tablespoon of citric acid per 4 ½ cups of boiling water. Showerheads are hollow and will float, most likely with the holes facing up—which clearly defeats the purpose of this strategy. Use anything heavy and heat-resistant to keep it submerged. I used a jar of olives, but I’m sure you can come up with something better.
Once your showerhead is securely submerged, leave it soaking for 15 minutes before rinsing with cold water. If there’s any residue still sticking to the piece at this point, you should be able to easily scrub it away using a small brush.
Screw it back in place and enjoy your (at least slightly) improved water pressure.
How to use citric acid to clean an espresso machine
You probably spent a lot of money on that fancy-looking appliance you use to make your delicious coffee, but what’s the point when your cup of morning glory has a slight taste of rust and metal? If you want to find the likely culprit of this travesty, look no further than the minerals in the water you’re using.
I’m sure you’re on to it by now, so let’s cut to the chase and get rid of that mineral residue. To descale your espresso machine, just fill the water reservoir with a solution of 2 tablespoons of citric acid for every quart of water, stir it to fully dissolve the crystals, and run the machine normally.
[Related: Are your cleaning products really green? Here’s how to tell.]
The mineral buildup will come out along with the citric acid solution. (Please don’t drink it.) If you see a lot of buildup, it might be worth it to run some fresh citric acid solution through your machine once or twice more. When you’re satisfied, run the machine one final time with clean water.
Depending on your water source, you might want to repeat the process every 30 or 60 days.
How to use citric acid to clean shower doors
I don’t think I need to keep singing the praises of citric acid, but on top of everything else, citric acid will also help you get rid of hard water stains on shower doors. That gunk is basically just mineral buildup.
You’ll need a little help from high temperatures, though. Using a citric acid to water ratio of 2 1/2 tablespoons per 1 cup of hot water, pour the solution on the door. Let it act for 15 minutes before rinsing. You might need to scrub a little with a sponge or rag, but the buildup should be loose and the stains should come off easily.
This story has been updated. It was originally published on November 5, 2020.