Potassium metabisulfite reaction with mug

[tacomaguy20]

Hi guys, I made what seems to be a mistake of using a ceramic coffee mug to make a 10% solution of potassium metabisulfite to add to my wine. After adding the sulfite, I cleaned my mug and it now has developed some sort of white mineral/substance on the outside and inside. It looks like it's cracked but the substance is easily wiped off or washed off but it returns after washing and drying. I've now washed it several times. Any idea what this might be? Could there have been a bad reaction to the ceramic? Do you think it's toxic? I posted asking in another forum but I think you may be the metabisulfite experts over here. Any ideas?

 

[Bossbaby]

Could it have just cleaned and brightened the cracks that were there and stained until now?

 

[tacomaguy20]

Could it have just cleaned and brightened the cracks that were there and stained until now?

No the mug was relatively new and I don't see any cracks. It's just developing that white substance so it looks cracked.

 

[Boatboy24]

Pic of the inside looks like a catfish. I have nothing else to offer.

 

[stickman]

Is the mug new or old? We have some coffee cups that have similar lines, except the lines in our cups are stained dark because of being used for coffee. The lines on your mug are probably due to very fine cracks in the glaze that allowed some of the sulfite solution to migrate between, and once the water portion evaporates the previously dissolved solids appear. It's not likely to have caused any issues for the 10% sulfite solution, though for the future it would be best to use a plastic bottle or Pyrex measuring cup etc.

 

[Dom Lausic]

Glass is the way to go! I ordered a set of glass beakers from Amazon, 50 mL to 1000 mL. Great for mixing all of you additions, rehydrating yeast, etc. The set cost about $25 CAD. It was a great buy!

 

[Venatorscribe]

Same as above. I use glass. Except I use mid size drinking glasses as my beakers and half the price. i don't know why the K Meta would have that effect. unless it is something related to a mild interaction with the glazing. Best not to use that mug again.

 

[Rice_Guy]

the appearance is what I would expect from stress cracks, ex where part of the object is hot and cold is applied possibly going back to the cooling cycle out of the kiln.

A variety of salts and minerals are used to produce colors in glazing so we can expect there would be some reaction with metabisulphite. Very curious that the outside also has lines, this suggests that cracks penetrate the ceramic.

 

[tacomaguy20]

Is the mug new or old? We have some coffee cups that have similar lines, except the lines in our cups are stained dark because of being used for coffee. The lines on your mug are probably due to very fine cracks in the glaze that allowed some of the sulfite solution to migrate between, and once the water portion evaporates the previously dissolved solids appear. It's not likely to have caused any issues for the 10% sulfite solution, though for the future it would be best to use a plastic bottle or Pyrex measuring cup etc.

The mug is maybe a year old but I think I've only used it 8 times or so. I'm beginning to think most of these responses are right that there is some reaction with the glazing ...like maybe it wasn't sealed completely... or microfractures or something. But who knows. I tried wiping it with some vinegar and I think that white chemical didn't return as bad. I am planning on soaking it in some water mixed with vinegar and see what happens.

 

[Rice_Guy]

we use citric acid to drive the ionization of meta, ,,, therefore acid is probably involved. If cleaning I would start with alkali such as baking soda or ammonia.

 

[Scooter68]

Given the variety of glazes on ceramic mugs, it's hard to know if your K-Meta solution found a 'Weakness' or fault in the mug's glaze. If you have any other mugs from the same batch, I would be careful using them.

Example - At Bed,Bath and the Behind, I saw several ceramic tooth brush holders that were clearly marked on the bottom "Not for Drinking use." Yeah, I'm going to put my toothbrush into a container like that???