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Thread: Cleaning Mukka Pot

  1. #1
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    Cleaning Mukka Pot

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi,

    Bought a Bialetti Mukka Pot recently, happy with the coffee, but the aluminium seems to be corroding a bit, getting dull and black points in the base. I think its due to being put away wet.

    Is there any good way to clean it up, or is it normal with an aluminium pot. I was thinking of using some oxyper (sodium percarbonate) to clean it up, anyone got any experience with galvanic corriosion and this.

    Or should I just leave it.

    Thanks in advance,

    Sam

  2. #2
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    Re: Cleaning Mukka Pot

    Sam,

    Galvanic corrosion is where you have two dissimilar metals in contact with resulting corrosion at the contact surface. Galvanic usually eats away at the aluminium pretty badly (you get pitting in the surface). Sounds like you have some oxidation ocurring on the surface which is not as bad and is usally limited to the outer surface only. You can give it a light polish with a scotch brite pad and that should remove the oxidation, however they usually leave scratch marks. It would be better to track down a metal polish at your local hardware or auto shop that will remove the oxide and leave a better finish. Try and dry it out first before putting it away as standing water will lead to the same problem again.

    Matt

  3. #3
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    Re: Cleaning Mukka Pot

    Cool, I think the major problem is putting it away wet.

    Cheers

  4. #4
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    Re: Cleaning Mukka Pot

    Yeah, mine used to frequently get white furry stuff on the bottom from some kind of reaction which could be washed away but was quite disconcerting. In the end I bought a stainless steel moka, and then about a month later invested in Silvia. I wouldnt really recommend the Aluminium ones after that, even though they are traditional and nice looking.

  5. #5
    Senior Member Lovey's Avatar
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    Re: Cleaning Mukka Pot

    Yeah, mine used to frequently get white furry stuff on the bottom from some kind of reaction which could be washed away but was quite disconcerting.
    Err dude, thats not a galvanic reaction, thats mould. :P
    The easiest way to avoid this problem is to put the empy base back onto a hotplate at a low temperature for a little while to dry it out before you put it away.
    All the best,
    Steve

  6. #6
    Senior Member robusto's Avatar
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    Re: Cleaning Mukka Pot

    Yes, thats mould alright, likes to feed on all that black coffee residue. The way to prevent it is to clean it thoroughly, and let it air.

    Little can be done about the aluminium corroding. Many of the newer mocha pots are made from unsuitable aluminium -- the gauge is too light to start with, and it fails to stand up to the rigours of daily heating, cooling cycles. The old fashioned ones were very thick and of a corrosion-resistant alloy.

    Galvanic corrosion, as Matt G says, is caused when dissimilar metals rough each other in a particular environment: usually water, or moist air. The issue with the mocha pot is not so much galvanic as straight out corrosion because that is what inferior grades of aluminium do: they "rust".

    Stainless steel is better, but even these can have problems with discolouration around the base where theyre heated.

    Buy from a specialist dealer rather than a gift shop, and unfortunately you get what you pay for, so the better ones are relatively expensive.

    Robusto

  7. #7
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    Re: Cleaning Mukka Pot

    Behmor Brazen - $249 - Free Freight
    Im very sceptical about the mould theory, for a number of reasons.

    First, the bottom compartment doesnt contain coffee. It contains water, which is boiled. Although the air does indeed contain mould spores, and some of these are highly resilient, if this was the cause of the white deposits then we could expect to see it on anything that has contained boiled water. This isnt the case - not in my kitchen anyway ;-)

    The aluminium container could indeed be of a low grade. I presume this means that it contains plenty of impurities. Aluminium itself oxidises rapidly on contact with air, to produce aluminum oxide. This is an extremely tough and unreactive substance, so it isnt going to react with boiling water. The impurities in the metal could react with the boiling water, and form some sort of salts which may come out of solution as the water evaporates. Its possible that this is what is happening, although I dont have any evidence to support this.

    Another possibility that occurs to me is that there is some sort of catalytic reaction happening, possibly breaking down the non-aluminium metals in the container. Ive noticed that the deposits occur very rapidly.

    I left a mokka machine out while still wet a few days ago, and saw that the white deposits had started to form on the water droplets within it, actually floating on top of the water droplets, and not on the metal surface. So the final alternative which occurs to me is that the deposits are simply salts in the water, although I dont see this on any other containers in my kitchen, so Id probably dismiss this as well.

    In short, I dont know what causes the marks, but I find the mould hypothesis quite unlikely. Then again, I cant prove any of the alternatives Ive listed! ;-)

    Someone must know the answer!



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