If the inside of your electric kettle is looking a little (or a lot) chalky, you’re going to need more than dish soap to get it clean.
Not surprisingly, the internet is rich with electric kettle cleaning tips. The most popular involves filling the inside of the kettle with equal parts water and white vinegar, bringing it to a boil, then letting it sit for about half an hour before rinsing.
Now, I love to clean with vinegar, but it’s not everyone’s cup of tea—especially because boiling a strong vinegar solution leaves a lingering vinegar smell in the air, often for hours. Sometimes it can be so potent you get a phantom vinegar taste in your mouth too!
My method doesn’t use vinegar, but it’s equally safe and it won’t leave your house smelling like a pickle factory. In fact, I happen to think my secret ingredient—food-grade citric acid—actually leaves a faintly pleasant scent in the air.
What is citric acid?
Citric acid is a compound originally derived from citrus fruits (it occurs naturally in lemon juice), and while it has some antibacterial properties, its real benefit is as a descaler. I use a crystal/powder form of citric acid to make a super-affordable DIY descaling/cleaning solution for my countertop ice maker and my Nespresso machine, and cleaning my electric kettle with citric acid is even easier.
What’s the white stuff on the inside of a kettle?
Before you clean your electric kettle, you should understand what’s making it look so dingy. The white, chalky stuff on the inside of a tea kettle is limescale, a buildup of minerals—primarily calcium and magnesium—that are present in all tap water. When water evaporates from a still-hot, nearly empty kettle, remaining calcium and magnesium crystallize into calcium carbonate (not to be confused with sodium bicarbonate, a.k.a. baking soda).
You’ve probably seen similar mineral deposits around the inside of your faucet spouts, on your showerhead, and in your coffee maker. There’s likely limescale buildup inside your hot water pipes too—and it could be in your cold water pipes if your municipality has noticeably hard water.
Is limescale dangerous?
It’s possible for limescale to harbor bacteria if it lingers in a kettle. Theoretically, this shouldn’t be an issue, since boiling water is often used to kill bacteria. However, according to the CDC, this is only effective if the bacteria is in contact with water at a rolling boil for at least one minute at sea level (it takes even longer at higher elevations). And if you’re like me, you remove your kettle from the electric heating element or stovetop the second it beeps or whistles at you to signal that the water has reached its boiling point of 212ºF. And if your target temp is even lower for pour-over coffee or specific types of tea, your water will never reach a rolling boil.