I have a stainless steel thermos and had always cleaned it with Crystal dish soap and had no problem. I was always using tea, however this time I used liquid dish soap. The man used coffee with the cream in it and the coffee came out tasting sour. What happened?
Went online this morning to ask if it was safe to clean a stainless steel thermos using bleach. What I got was suggestions to use hydrogen peroxide mixed with baking soda and water or, dishwasher detergent (Cascade) and boiling water. I chose the "Cascade" method. This worked wonderfully; cleaned my coffee blackened, large thermos to a like new finish in 15 minutes with just two rounded tablespoons of detergent. Thank you David K., JMRoss, Susan from ThriftyFun, and others who suggested this method. Thank you also, Sandy, for letting me know bleach was a bad idea, that it would damage the seal/weld.
I needed my Thermos cleaned quick! I used about a half box of soda and at least a pint of hydrogen peroxide and the rest water. I have the biggest stainless steel Thermos I could buy actually made by "Thermos." It really works!! In about two hours it looked like new on the inside!
By Dean T.11/26/2009
I wanted to be the third to say thanks for the tip on hydrogen peroxide and baking soda. I cleaned both a thermos and a baking pan (cookie sheet) that had Thanksgiving sweet potatoes residue stuck on it -- I didn't want to scrape off the non-stick on the pan, and the mixture worked great.
Do mix the hydrogen peroxide and baking soda in a thermos or glass or some other container so you can shake it and mix everything before pouring in on the baking pan. Otherwise clumps of baking soda might block the solution from cleaning parts of the pan.
Back to the thermos cleaning: I also experimented with how much hydrogen peroxide is needed. I found that about 1"+ of hydrogen peroxide, and then regular tap water combined with about 1/5 box of baking soda set over night would clean a moderately coffee-stained thermos just fine. I did what others suggested, and put the lid on and shake it first, and then remove the lid. I let the thermos sit overnight, and dumped the floaters and any undisolved baking soda in the toilet. It might not have clogged the sink, but I didn't want to take a chance.
Thanks again to those who gave this initial tip!
By D. Wright06/12/2009
This turned into a teaching moment for my seven years old granddaughter, Mikae'lyn. I added vinegar to the peroxide and baking soda and foam shot out of the carafe. So, we experimented. The result was from the acidity in the vinegar reacting with the baking soda. And...it cleaned it good! :<)
I'm going to assume you know how to cleanse and rinse properly as you've been already doing that.
I'd say the cream was probably sour.
By vickie guy04/21/2009
Maggie is right. Start over and clean again with baking soda. It's a little bit abrasive, just enough to clean well.
Did you rinse it well enough?
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Coffee stains in Stainless steel thermos. How can they be removed?
Shirl from Medford, OR
Lemon Juice (fresh or bottled) or Vinegar. First take about a cup of any one of these, swish it around the thermos without diluting it then mix in some water (about 1 part Vinegar or Lemon Juice & about 3 or 4 parts of water) and soak at least a few hours or overnight, then rinse with warm water. This is how they recommend you clean out coffee pots, so if Vinegar can clean coffee stains, I'm sure it will clean out your thermos.
One more option if none of these work. I've bought Stainless Steal Thermos used at second hand stores before and to rid them of any germs, I've used a small amount of bleach (about 1 to 2 inches in the bottom) and added warm water. This worked great for me. Bleach works great on Plastic and Glass Thermos too! (09/08/2006)
By David K.
By Bob W
By Douglas P
I just wanted to second where someone said to use hydrogen peroxide and baking soda. I have two thermos' and one of them was really nasty. It was totally black and I tried lots of different ways to clean it. Nothing worked. I bought some of the big hydrogen peroxide bottles from Costco. I filled the offensive thermos with it and used about 1/3 to 1/2 a normal box of baking soda. I put the top on and shook it hard and then took the top off and let it sit over night.
The following morning I saw a layer of black substance floating on top of the liquid. I dumped the hydrogen peroxide/soda mix out and rinsed it out. It was totally clean inside. It looked new, no exaggeration. I even showed my wife and she too was amazed. This really works and it couldn't be easier. You won't be disappointed, I promise. (12/11/2008)
By Roger D
Incredible! I just used the Cascade Liquid Dishwasher Soap method discussed here. I put a little less than a dishwasher loads worth in our Kitchen Aid stainless steel 10 cup pot, shook it a little to spread it evenly along the bottom, put a pot of water on to boil (about 5-6 cups of water) and then poured the water into the coffee pot that was sitting with the Cascade in it.
I put the sealed lid on the pot (I was careful to shake the pot moderately in a level position to let the pressure in the pot escape out of the vented pouring top, given the experience of one of the writer's below on it exploding a bit when the pot was not shaken to let it vent) and after about a minute of shaking, let the pot sit for another 2-3 minutes on the counter.
I then came back, gave the pot another shaking for less than a minute and then poured out the contents. It was incredible - the pot looked brand new inside with every bit of built up coffee crud removed. Definitely saved the pot from the scrap heap and since you know Cascade is safe since you wash dishes with it, I'm happy to just rinse out the pot and get fresh coffee the way it's supposed to taste.
Thank you to whomever figured out this cleansing recipe. It is a real demonstration on the power of concentrated Cascade, but it definitely gets the job done fast and easy with no physical effort. (01/31/2009)
By N Cheng
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