Reusing Sodium Metabisulphite? Safe?

[Rocky]

This discussion reminds me of a very old joke I heard, perhaps 70 years ago.

A Scotsman goes to a tire manufacturer and asks the manager, "How much to have this prophylactic vulcanized?" The manager looks at the rubber and says, "It would be about $1.25, but you can buy a new one for $1.50." So the Scotsman thanks the manager and leaves. He comes back a day later with the prophylactic and says, "The Regiment wants it vulcanized."

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[sour_grapes]

I discovered its loss of strength/activity 'after' bottling... :/

What was the specific observation that you made that led you to conclude that it had lost its efficacy?

 

[cmason1957]

I think i I wanted to test if my K-Meta were good, I'd mix up a one gallon batch and take a whiff (or let the cellar rat take that whiff). Mine always lets me know it's good when mixing.

 

[MercerWine]

What was the specific observation that you made that led you to conclude that it had lost its efficacy?

Even at higher mix ratios, bacteria continue to survive and thrive, as if no SMBS were used.

 

[MercerWine]

I think i I wanted to test if my K-Meta were good, I'd mix up a one gallon batch and take a whiff (or let the cellar rat take that whiff). Mine always lets me know it's good when mixing.

I tend to agree with that assessment until the SMBS stopped killing bacteria despite having a similar nasal reaction.

 

[sour_grapes]

Even at higher mix ratios, bacteria continue to survive and thrive, as if no SMBS were used.

How did you observe the bacteria? Did they form mats, or perhaps flowers of wine?

 

[MercerWine]

How did you observe the bacteria? Did they form mats, or perhaps flowers of wine?

Nothing more than the empirical evidence of fart bubbles...

 

[sour_grapes]

This why I asked. You have us all chasing down the chemistry of Na-meta, etc., when it could just be outgassing.

 

[Rice_Guy]

The SMBS is in powder form
and stored in smaller air-tight tubs.
I discovered its loss of strength/activity 'after' bottling...

* if you know what the free SO2 is you could adjust the treatment to a higher dosage. (ex 110% of the calculator ) Most folks won’t identify sulfite flavor at the legal limit. As a home wine maker most of us don’t even track commercial limits.
* if anyone looks at this problem in the future they should consider sealing the dry powder in plastic vacuum pouches to keep oxygen and humidity out of the product and then put the pouch in a PET or wide mouth canning container as a secondary “everything other than SO2 “ barrier.

 

[MercerWine]

This why I asked. You have us all chasing down the chemistry of Na-meta, etc., when it could just be outgassing.

Well, yes I am trying to 'chase down the chemistry' since I have so much exhausted powder and would like to reactivate it if possible...

 

[Hazelemere]

Is it possible to rejuvenate old, unused SMBS...? I purchased 70kilo by mistake and it has aged out of strength.
I'd like to recharge it if possible. I have a pyrolysis oven and wonder if a heat treatment would do the job...?
Any thoughts or experiences?

heat will destroy it. Bleach will also destroy it. It decomposes slowly over time as it absorbs oxygen and moisture. If it is lumpy it is definitely done. If it is really powdery and sealed properly it might be okay. 70 kilos?

 

[wineview]

Why would anyone want to reuse it??? I use it, and then kill the bacteria in the sink drain. I also store some in empty carboys but always dump it.

Richard L.

Septic system users……beware.

 

[MercerWine]

heat will destroy it. Bleach will also destroy it. It decomposes slowly over time as it absorbs oxygen and moisture. If it is lumpy it is definitely done. If it is really powdery and sealed properly it might be okay. 70 kilos?

Since the production uses both heat and evaporation it only seems reasonable that it would be possible to reactivate it... Yes, 70 Kilos stored in sealed containers from the original packaging 4 years ago.

 

[sour_grapes]

You really owe it to yourself to verify (with some evidence) that you have any untoward microbial activity.

 

[Ohio Bob]

As a septic system owner, I totally agree that dumping it down the drain would be a bad idea. I don’t dump more than a gallon of any wine chemicals, idophor sanitizer, PBW 5Star, or kmeta.

I would consider using it around the yard to deter nuisance varmints. Since we expect it to degrade in the presence of moisture, 70 kilos might last a year.

 

[Hazelemere]

Since the production uses both heat and evaporation it only seems reasonable that it would be possible to reactivate it... Yes, 70 Kilos stored in sealed containers from the original packaging 4 years ago.