Ah the humble flask. Many of us use thermal or vacuum flasks to get our hot drink fix on-the-go. They’re also undeniably handy for picnics and carrying soup on colder days. This is great for cutting down on single-use plastic (and saving us some cash at the same time).
However, you will need to clean your flask after each use, and the narrow neck can make it a little awkward to clean. While a quick wash is fine most days, you’ll want to give it a thorough clean now and then to keep mould, bacteria and nasty niffs away. Here’s how to clean a flask.
Cleaning a flask with washing up liquid
Before you start looking for the best way to clean a flask do check for any manufacturer’s guidelines (if you’ve chucked them away, have a look on the brand’s website).
- Take off the cup and stopper.
- Pour away any liquid that’s left in the flask.
- Give it a quick rinse.
- Don’t soak the flask, as submerging it in water for a long period of time can damage it.
- Using warm water and a mild washing-up liquid, wash both the interior and exterior of your flask. You might be able to use a soft cloth or sponge. However, if the neck is too narrow to get your hand in, you’ll need to use a soft-bristled bottle brush or toothbrush.
- Rinse thoroughly to remove all traces of washing-up liquid. It’s best to do this using hot, running water.
How to clean a Thermos flask stopper
Some stoppers can be washed in the dishwasher. If yours can’t, use a mild washing up liquid and an old soft bristled toothbrush to clean it. Make sure you get in all the crevices. And rinse it thoroughly, or your next latte could taste rather soapy.
You won’t be able to reach some parts of the stopper, so it’s a good idea to give the whole thing an extra good clean sometimes, using a teaspoon of baking soda dissolved in a cup of warm water, and that soft bristled toothbrush.
Don’t forget to wash the cup out, too. Follow the steps for cleaning your flask that we’ve set out above.
How to dry a flask
Now that you know the basics on how to clean a Thermos flask, it’s time to learn how to dry it efficiently. If you have time, allow your flask, stopper and cup to drain and air-dry. Open up the stopper to allow air to circulate. Then, use a clean towel to dry off any excess liquid. Make sure it’s completely dry before you put it away.