My Klean Kanteen tastes like I'm carrying spare change in my mouth. Fixes?
July 18, 2012 4:27 PM   Subscribe

Last week I bought a 16oz Klean Kanteen Insulated (double-walled, hot/cold) container to replace a favorite Thermos (also stainless) that is no longer made.

I have no complaints with the leakproofness (a true screw-on sealed lid) or the thermal properties of the Klean Kanteen, but the taste is awful.

It's been thoroughly washed with soap and with baking soda. But still: metal tasting coffee. I have tossed half a dozen cups now.

Any tips?

It's otherwise perfect for what I need and I would like to be able to use it for years to come. Found a couple threads on plastic taste but noting on steel.
posted by quarterframer to Food & Drink (12 answers total) 4 users marked this as a favorite
I bet that comes from putting your mouth on the edge of the bottle, if you pour the water into a glass and drink it, does it still taste metallic? I don't know if there's anything you can really do except change your drinking technique (you kind of want to pour it into your mouth instead of drinking out of it like a glass).
posted by muddgirl at 4:31 PM on July 18, 2012

You might have better results by using the "sport top" mouthpiece, which you can buy separately.
posted by BlahLaLa at 4:34 PM on July 18, 2012

your Klean Kanteen is still very new, maybe it just needs time to build up a layer of coffee seasoning? You mention your old favorite is no longer made, so I imagine you were using it for a long time and maybe it had a "metal-o-guard" layer of coffee built up on it.

Maybe you could let a really strong brew season the thermos?


a post from jkoll42 posted 1/2/10 mentions how he has to season the thermos each time he cleans it, or he can taste it. He doesn't specify a "metal" taste, but he does talk about how stainless can give the coffee a taste.

A later post states that the process goes:
"Basically, when I use backflush detergent to clean everything out it does a great job, but first use I can pick up a little off taste from the stainless. After I clean everything I pull out my stash of garbage beans and run a pot. Fill up my stainless stuff and let it sit for a bit. Dump, rinse. It saves me from having a day of 'something tastes a little off with this coffee' "
posted by Momorama at 4:39 PM on July 18, 2012 [1 favorite]

What about a rinse with vinegar, followed by some water (to get the vinegar out)? That works to clean the residue out of my coffeemaker, but I've never tried on a stainless thermos.

Or maybe leave it out in the sun for a few days? This works to get funky tastes out of plastic.

Please report back if you do find anything that works. I've had this same problem myself, and I end up buying more coffee than I really should.
posted by SuperSquirrel at 4:51 PM on July 18, 2012

Response by poster: I don't have the "sport top" but for a couple of days I tried pouring into a ceramic mug rather than drinking directly from the KK. Still metal-y.

@Momorama + SuperSquirrel, I will try all of these things, although the "seasoning" is not something that makes practical sense long term. Will report back. I would like to see this mug succeed.
posted by quarterframer at 5:05 PM on July 18, 2012

Heads up: that sport top is not remotely waterproof.
posted by griphus at 5:23 PM on July 18, 2012 [2 favorites]

AH! I know this one!

Baking soda reacts with stainless steel in weird ways and creates weird flavors. I do not know the science behind it, but here's some anecdotal evidence:

We had this problem at a coffee roastery where I worked: our tasting spoons were stainless steel, but our tasting cups were porcelain. We didn't wash them with soap, because most soaps leave a film that we could taste when doing really careful cuppings. So we started washing everything with baking soda. This made things far worse, and the only thing we could think of is some sort of weird, small reaction between the Stainless Steel and the baking soda. So, then we started washing the spoons with boiling water and puro-caffe, and the cups with baking aftertaste of anything. This worked really well for technical tastings, nerdier than just drinking really fucking good coffee out of a mug.


I would use boiling water & Puro-Caffe to clean your thermos, not soap or baking soda. Stuff works really well.
posted by furnace.heart at 5:26 PM on July 18, 2012 [7 favorites]

I have heard that coffee pots and things really ought to be cleaned with vinegar. This makes a sort of sense given furnace.heart's answer above, as vinegar is acidic whereas baking soda is alkaline. Perhaps you could try cleaning your bottle with vinegar and then rinsing with water.

Alternatively, you could try just rinsing with water. Over time you will get a film of coffee residue on the inside of the bottle (the "seasoning") which will definitely prevent whatever you put in there from tasting like anything but coffee. If you intend to drink only coffee from this bottle, then I would go with that. It may seem a little gross, but frankly I doubt if there's any health risk at all as boiling hot coffee is a pretty inhospitable environment for bacteria.
posted by Scientist at 9:05 PM on July 18, 2012

Response by poster: @furnace.heart, thanks for sharing that experience. Puro-Caffe on order. Will update you all.

@griphus, thanks for the warning! I loathe both handles and "sippy cup" style lids on my mugs. I prefer screw on, sealed caps which is part of why I really dig the KK and hope it will work out.
posted by quarterframer at 6:39 AM on July 19, 2012

In case it helps - and in case nothing can make the Klean Kanteen work for you - this Thermos is stainless, has a screw-on lid, seals REALLY well when closed, and last time I used mine on a road trip coffee put in the thing at 8 AM was still hot when I drank the last sip at 2:30 PM.

No weird metallic taste from the thing, but god damn do you ever need to be sure the temperature is right when drinking from it - if you use the non-spill top, and the coffee is too hot when poured in, it is NOT going to cool off fast enough for you to drink it any time soon.
posted by caution live frogs at 6:59 AM on July 19, 2012

For some reason I notice my Kleen Kanteen leaves less of a metallic taste when I rinse it with cold water after washing it.
posted by a red so deep at 12:27 PM on July 20, 2012

Response by poster: Thanks all.


Vinegar: No change.
Puro-Caffe: No change.
Rinsing only with water for a week: Still bad.
Buying a different brand: Worked perfectly.
posted by quarterframer at 12:00 PM on August 1, 2012 [1 favorite]

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