At La termoteca we believe that a good flask is made to accompany you for years, in coffees on the way to work, impromptu excursions or tea breaks in the office.
But to keep it like new, it needs a little love and care. Taking good care of it not only extends its lifespan but also maintains its thermal performance and the flavor of your drinks.
Here we tell you how to clean your flask step by step , what to do (and what not to do) , and how to keep it perfect day after day.
Why is it important to clean the flasks frequently?
Although it seems obvious, we often forget: flasks are constantly in contact with hot and cold liquids, and with traces of coffee, tea, or milk. If you don't clean them properly, these residues can cause odors or affect the taste.
Besides:
● Stainless steel, although very hygienic, can accumulate small particles if it is not rinsed well.
● Proper maintenance keeps the vacuum insulation in perfect condition.
● And most importantly: it helps prevent bacteria from growing on the seals or lid.
💡 Tip from La termoteca: Clean your flask with warm water and mild soap after each use. If you use it daily for coffee or tea, give it a more thorough cleaning once a week.
Daily cleaning: simple and effective
- Rinse immediately after use
Rinse it with warm water to avoid stains and odors. - Use a soft brush or a long sponge
Avoid metal scouring pads: they could scratch the interior and affect the protective layer of the stainless steel. - Wash it with neutral soap
A few drops are enough. Insert the brush, rub gently, and rinse well. - Air dry with the lid open.
Leave it uncovered so it can air out and no moisture remains inside.
Deep cleaning: once a week
If you notice a lingering odor or coffee or tea stains, do a natural cleaning with products you have at home:
Option 1: Baking soda and white vinegar
- Fill the flask with hot water.
- Add a tablespoon of baking soda and a splash of white vinegar.
- Let it rest for 15-30 minutes.
- Shake gently, empty and rinse several times.
Option 2: Baking soda and lemon
- Squeeze half a lemon into the thermos.
- Add a tablespoon of baking soda and hot water.
- Leave on for half an hour and rinse.
Both mixtures eliminate odors, disinfect, and keep steel shiny without harsh products.
💬 Frequently Asked Question:
Can I put the thermos in the dishwasher?
In most cases, it is not recommended . Extreme heat and detergents can damage the silicone gaskets and vacuum seal.
👉 At La termoteca we always indicate on each model whether or not it is dishwasher safe (check the data sheet for your water heater).
Common mistakes when cleaning your flask
Avoid these actions that can shorten its lifespan:
● Do not use bleach or abrasive products.
● Scrub with metal scouring pads.
● Close the thermos while it is still wet.
Extra tip: store the flask with the lid off when not in use. This will prevent odors.
How to care for gaskets, lids and exterior
The inside isn't everything — the covers and gaskets also deserve attention.
● Remove the lid and clean each part (especially if it has threads or silicone seals).
● Dry thoroughly before reassembling.
For the exterior:
● Clean with a damp cloth and neutral soap.
● If the finish is matte or colored, avoid products with alcohol.
Frequently Asked Questions
Why does my flask smell bad even after I wash it?
There's probably residue on the lid or seals. Remove them, clean them with vinegar, and let them dry in the sun.
Can I use cleaning tablets for thermoses or flasks?
Yes, but make sure they are specifically for stainless steel and chlorine-free.
What do I do if the flask has lost its thermal capacity?
If you notice it no longer retains heat or cold, the internal vacuum seal may be damaged. In that case, it cannot be repaired, but proper care will significantly slow down the deterioration.
