How to clean and descale your kettle to remove limescale

Are you seeing annoying white flakes in your cup of tea or coffee? Urgh! It might be time to clean out your kettle. Let’s learn how. 

Whether you use an electric or stovetop kettle, over time, you’ll notice mineral buildup inside your kettle. While gross, it’s no big deal. Luckily, it’s easy to clean and remove this calcified scum. 

In this article, we’ll tackle why this build up happens (limescale) and the easiest way to clean the inside of your kettle. 

---

What is that buildup?

According to the U.S. Geological Survey, hard water has more minerals, largely calcium and magnesium, dissolved in it. 

Depending on how hard your tap water is, you may begin to see a translucent layer of white deposit stick to the bottom and sides of your kettle within a few months of frequent usage.

This white deposit, called limescale, builds up from the minerals found in the tap water. The minerals precipitate and form a layer inside your kettle.

NOTE: While white is the most common color (calcium carbonate), the limescale can be green, brown, or pink depending on the minerals present (magnesium and iron compounds change the color).

When there’s a lot of limescale, you may see tiny chalky flakes floating in your boiled water. These flaky deposits cling to your glasses and pollute your cup of tea made from water boiled in your kettle. 

While these minerals aren’t harmful, they look awful. Let’s learn how you can clean out these mineral deposits. 

---

How to clean out an electric kettle

Cleaning out limescale is often called descaling. 

Even though this article focuses on descaling your kettle, which is the most common, the same steps for descaling a kettle apply to all sorts of household items that can accumulate limescale. 

For example, you can use this technique to clean out cloudy deposits in your prized pots and pans, teapots, and even in your sink or faucet. 

Here’s the most important point to remember when cleaning out your kettle.

TIP #1: Use acid to descale.

TIP: You may want to open a window for ventilation. When vinegar boils, it can irritate your nose and eyes. Avoid standing next to your kettle while the vinegar is boiling.

---

Tips for success

• I’ve tried this technique without boiling the vinegar, and it doesn’t work as well. I found that boiling the vinegar cleans more effectively than soaking room-temperature vinegar in the kettle for several hours.
• Allowing the vinegar to sit in the kettle for at least 30 minutes to give the acid enough time to remove the limescale. 
• Why fill the kettle only half way? The vinegar froths when it boils. If you fill the kettle full of vinegar, you’ll have a mess when the vinegar bubbles and overflows out of the kettle.
• If you have marble countertops, the vinegar will etch your beautiful countertops. Avoid descaling the kettle near any marble or limestone surfaces. Move the kettle elsewhere for this cleaning process.
• Although you can repeat the steps as many times as desired until the kettle is descaled to your satisfaction, I usually do 1-2 rounds. After 2 rounds, I feel that you get diminishing marginal returns on your time and effort. 

I do this cleaning routine less than once a year, as needed, usually when the limescale bothers me.

Alternative ingredients

Lately, I’ve been using powdered citric acid instead of white vinegar to descale my kettle. 

I bought the citric acid for making cheese and have a lot left over. I add a little water to ½ cup of citric acid to make a more concentrated acidic solution.

Because you can use any acid, all kinds of vinegar and some citrus juice would work for descaling. 

Different types of acid you can use to descale the kettle:

• Lemon or lime juice
• Vinegar (white, apple cider, malt, etc.)
• Soft drinks, like Coca-Cola (though less effective than white vinegar)

White vinegar (acetic acid) is the cheapest option per volume. (I buy 2 gallons from Costco at a very affordable price, about $4). Lemons cost 79¢ each (at least in Boulder) and provide less than ½ cup of liquid.

Furthermore, descaling with white vinegar is the most cost effective because it has a lower pH, plus it’s cheaper and easier to buy. 

Save your lemons for making lemonade, mānuka honey and lemon tea, or garlic-lemon salad dressing.

FINAL TIP:  I see advice on the Web that suggests descaling with baking soda. Terrible advice. Why? The baking soda makes an alkaline solution, which doesn’t trigger a chemical reaction with the carbonate to dissolve the limescale. Stick with acid for cleaning out the mineral deposits. 

READ NEXT: Why Electric Kettles Rock: Which One Is Right For You?