Is it OK to leave water in a kettle?

When we boil water, usually we need it right away because that boiled water is going to be utilized in a myriad of activities such as bathing, cooking, and drinking. In some cases, we can’t attend to the water right away or due to how busy life can get, we might even end up forgetting to go back to the water in the kettle. In this article, we’ll discuss whether it is ok to leave water in a kettle or not. 

Should you always empty the kettle?

The simplest answer for this question is yes, you should always empty the kettle. The main reason behind that is due to scale formation. Any water that’s left inside the kettle results in the buildup of limescale.

For those who are unaware of what limescale is, these are the white and chalky buildups that form both inside and outside of the kettle – the result of Calcium and Magnesium particles that’s present in hard or tap water.

Removing limescale is important because of the following reasons:

• Limescale makes the boiled water taste funny. This makes coffee and tea drinks taste somewhat off and unusual because of the limescale altering the quality of the boiled water.
• Limescale affects the kettle’s lifespan and efficiency. Not only does it weaken the performance of the kettle to heat water but it makes the kettle more likely to get replaced in the longer run.
• Speaking of coffee or tea, there have been instances of limescale floating in cups of coffee or tea and that is very unsightly.

Take note that despite being Calcium-based, limescale does not cause Kidney Stones. There’s no evidence drinking hard or tap water could contribute to that.

How to remove limescale?

Cleaning out limescale in the kettle isn’t a difficult task. You can utilize a shop-bought limescale remover to get rid of the limescale present in the kettle.

It is highly effective however do bear in mind that limescale removers have a minor side-effect of leaving behind a soapy taste in the water and are rather expensive in the longer run.

Alternatively, this can be done through the simplest of means through an acid solution. Fill up the kettle with equal parts water and equal parts acid (preferably Lemon Juice or Vinegar) and leave the kettle to soak for up to an hour. This should weaken the grip of the limescale on the kettle.

Once an hour has passed, that’s where you boil it, empty and repeat the process (but with water only) before you can start thoroughly rinsing the kettle.

Make sure you do the cleaning and descaling process on either a weekly or a monthly basis to keep your kettle at top performance. While the preparation can be longer compared to just buying a store-bought limescale remover, this has the additional benefit of being able to save up more money since you are not opting for expensive cleaning materials.

ADDITIONAL NOTE: A good alternative to Vinegar and Lemon Juice is Baking Soda. Even though it is a base, it still offers the same benefits in removing limescale present in the kettle.

Do kettles kill bacteria?

The kettle cannot kill bacteria on its own. The process of boiling the water inside the kettle does kill the bacteria. By bringing the water inside the kettle to a boil at 100 degrees Celsius (212 degrees Fahrenheit), destroys and eliminates any unwelcome microorganisms such as bacteria and parasites that are present in the water.

The kettle’s role is to be the water-heating vessel, so we can say that the kettle is contributing a part in killing bacteria in the water by providing a suitable area to hold the water that is needed to be heated and consumed afterward.

Can I Reboil water in my kettle?

The easiest answer to that question is “NO”. Never re-boil the water that’s present in your kettle. You are better off emptying the kettle, filling it up again, and heating a new batch than re-heating the previously heated water. There are two notable reasons why you don’t want to re-boil the water in the kettle – one is because it will negatively impact your brewed drinks and the second is a health-related matter.

1. First off, re-heating the water that’s already in a kettle is the nightmare of many coffee and tea enthusiasts. Boiled water is already flat-tasting to begin with but re-heating it again makes it taste even worse. In fact, if you would brew tea or coffee with re-heated water – the outcome is a tea with a very dull taste. You won’t be able to enjoy the full flavor of your brewed beverage if you are to re-heat a whole kettle.
2. It presents as a health hazard. Re-heating the kettle can lead to the over-concentration of certain chemicals that are already present in the water. Re-heating the water causes nitrates, arsenic, and fluoride to become more and more prevalent. This means that for every re-heating of the water, these chemicals will become more and more concentrated and can negatively impact your health. Keep in mind that if you are pregnant or have a compromised immune system, you are more vulnerable to the effects of nitrates, arsenic, or fluoride in the re-heated tap water.

ADDITIONAL NOTE: There is only one condition where you can re-heat water and that is if you’re using distilled or deionized water as they are already purified of any gases or elements that are present in ordinary water. Just a reminder, do not re-boil water that came from the faucet as these come in with the said elements that can become concentrated upon repeated re-heating.

In summary, re-boiling the water inside your kettle is a big No-No. Do not re-boil the water inside the kettle because aside from ruining what is an otherwise pleasant tea or coffee experience, you could put yourself at risk of health problems due to the concentrated chemicals in the water. Unless you are using deionized or distilled water, never re-boil the water in the kettle.

Let's recapitulate: Is it OK to leave water in a kettle?

No, it is never okay to leave water inside the kettle. Leaving water inside the kettle will result in limescale that will not only ruin the taste of hot beverages but will contribute to the shortened lifespan and weakened heating performance of the kettle. To avert that, you will need to de-scale the kettle on either a weekly or a monthly basis.

Next up, the kettle on its own cannot kill the bacteria but the boiling process does. The kettle’s role is to provide a suitable containment for the water that is to be heated to a boil – so basically, it’s playing a part in killing the microbes in the water.

Last but not least, is that re-boiling water does more harm than good. It makes the already flat-tasting boiled water taste even worse than before and on top of that is the possibility of running into health problems because of the over-concentration of certain chemicals in the water. Unless you are using deionized or distilled water, re-boiling water is never a good idea.