Tea stained flask

[canihaveonesomeroses]

I love making a flask of tea, settling down for a day WFH and then just topping up my cuppa as I work.

My flask however clearly doesn't like it - nasty tannin stains in it now 😫

I take my mug straight out of the dishwasher and wipe it with a cloth while it's still hot and the tannin stains come off easily, but I can't do that with my flask.

Any of you got a clever trick to help me clean my flask?

I just periodically leave mine filled with a bleach solution overnight, then rise & wash it well the next day. A bottle sponge could wipe out the inside for you to keep the stains at bay longer after it’s clean.

Denture tablets might get the stains off?? My mum always used them on tea stained mugs

this stuff is brilliant

https://astonish.co.uk/products/specialist-clean-revive?srsltid=AfmBOoqflRCQYw_8SrKB3m4ZUpDAnv2PVVXimax7M8gJ8wChWvWENleh&variant=40254406000819

I just use a milton tablet

Fill with a mix of bicarb of soda, lemon juice, white vinegar and boiling water - leave overnight and wipe/rinse in the morning

Sofa crystals

Many years ago I used to just rinse the flask out and then fill to about ½ full with warm water, then add 2 or 3 teaspoons of dry pearl barley. Put the lid on and shake like a cocktail shaker for 10 seconds or so. Empty it out and final rinse with clean water.

If gummy with milk or similar, a spot of WUL in the water as well.

Always came out like new.

If you plunge the flask with a bottle brush you risk breaking the inner glass skin. (assuming it’s the old style double glass flask)

Thank you all so much for these suggestions, I've no doubt my flask will be shiny again in no time!

You could also try a magic eraser sponge Or put the flask in the dishwasher as I have started doing - not sure if it’s recommended but now and again is fine in my experience.

Use a dishwasher tablet or powder directly in it with water.

@swimlyn has it. I use a handful of uncooked rice. No need for chemicals or scrubbing, really effective.

I just use bicarbonate of soda and it seems to work

I use denture tablets on my mugs with this issue.

Soda crystals cheap from the supermarket or somewhere like band m boiling water leave to soak for a little while then rinse well. Works wonders on a kettle too

Steradent tablet overnight

A teaspoon of laundry powder, add boiling water, leave overnight.

Same. About 2/3 Teaspoon in the flask, add boiling water and leave.
Alternatively you can use Oxyclean powder (I use it on stained cups, mugs, teapots). Just rinse very thoroughly.

I put my thermos flask in the dishwasher. All the paint has come off the outside but it seems otherwise unbothered.

I do the same. I pop a Steradent tablet in a stained mug or flask, leave it overnight and hey presto, it’s like brand new!

Just to let you know, I tried the bicarbonate of soda and boiling water trick as I had those to hand and the stain has nearly all gone! So pleased 😃 Will do it again tomorrow and see if the last bits comes off.

Pity that isn't something I can do for the light tannin stains on my teeth 🤣

@canihaveonesomeroses One of these will sort your teeth out 😁

https://amzn.eu/d/aaDTYrs

@canihaveonesomeroses One of these will sort your teeth out 😁

Tempting, if it will give me teeth as white as that 🤣

You need sofa crystals.