How to Descale a Kettle — Toronto Home Guide

Limescale — the white, chalky mineral deposit that forms on the interior of kettles — is calcium carbonate from dissolved minerals in tap water. It doesn't affect water safety, but it insulates the heating element, slowing heating and increasing energy use, and it can flake off into beverages. Toronto's tap water has moderate hardness; most kettles need descaling every 1–3 months depending on use.

White Vinegar Method

1. Fill the kettle with equal parts white vinegar and water — enough to cover the scale, at minimum half-full
2. Bring to a boil
3. Turn off and let sit for 30–60 minutes — the longer the soak, the more scale dissolves
4. Pour out the vinegar solution
5. Fill with fresh water and boil again to rinse out the vinegar taste — repeat this rinse once or twice
6. For stubborn scale on the spout or exterior, dip a cloth in undiluted vinegar and wipe the affected area

Citric Acid Method (Faster, No Vinegar Smell)

1. Dissolve 1 tablespoon of citric acid powder (available at grocery stores in the baking aisle) in a full kettle of water
2. Bring to a boil
3. Let sit 15–20 minutes
4. Pour out and rinse with two full boils of plain water

Citric acid dissolves scale just as effectively as vinegar but leaves no lingering smell or taste, making it the preferred method for frequent use.

Lemon Method

A half lemon squeezed into a full kettle of water and boiled is a mild descaler for light build-up and freshens the kettle at the same time. Less effective than vinegar or citric acid for significant scale.

Preventing Build-Up

• Empty the kettle after each use and rinse — standing water evaporates and leaves minerals behind
• Use filtered water if you live in a hard water area and descale frequently
• Do not leave boiled water sitting in the kettle for extended periods