To clean the sensitive and hard to reach inside of thermos flasks stained by coffee or tea put some baking powder into the empty, dry flask and pour water from a recently boiled kettle over it. Cover it up when all the foam has settled and leave it for half and hour or so. Repeat if necessary. Also works on pans etc.
How do you clean the inside of a flask?
Instructions
- Pour the vinegar or peroxide into the bottom of the thermos.
- Add the baking soda.
- Fill the remainder of the thermos with hot (the hotter the better) water.
- Let sit for several hours, like overnight. (Do not cap.)
- Dump the container and rinse thoroughly.
- Wipe out as much water as you can with the towel.
Is baking powder good for cleaning?
Baking soda and baking powder are not chemically the same, and so you should not substitute baking soda for baking powder when following a cleaning guide. Whilst baking powder may offer some cleaning effect, it really is just designed for baking, and so it is not recommended that you use it for any cleaning purposes.
