Sodium vs potassium metabisulphite

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Well, Bill, to state the obvious- potassium meta (K-meta) has potassium and sodium meta has sodium. ;) That's the only difference. People who are sensitive to salt and sodium in general should buy the k-meta.

It's used for two basic things in winemaking- for sulfiting the wine to preserve it and to inhibit oxidation- particularly for wines that will be aged more than a year or two. This is done at about 50 ppm (I don't have an so2 tester, so I just do the "every other racking" and at bottling additions) which is undetectable at that concentration. When you bottle, you can add it (along with k-sorbate) to help ensure that refermentation doesn't start if you are sweetening the wine. This is usually referred to as stabilization.

The other thing it's used for is sanitation. I usually use one-step for my equipment, but some just wash the equipment with a wine making cleanser and then sulfite for the sanitizing step.
 
K-meta (campden) can also be used to remove chlorine and chloromines from your brewing water. One tablet in 20 gallons will reduce both to insignificant levels of sulphate and chloride ions within minutes.
 
We use Sodium BiSulfite to treat our waste water from our cooling towers at work. We Keep a small amount of bleach(Chlorine) in our cooling towers to keep the bugs and algea from growing, then the blow down water is pumped to a canal down the road and treated with sodium Bisulfite to remove chlorine.
 
Hi,

I'm super new, and had this question too. I bought both. Both say Campden tablets. All the recipes I've read say campden tablets. Is this just a diet coke / diet pepsi difference? I don't like sodium, but I don't know if I like potassium..

Seriously, are they interchangeable?

Why would one choose one over the other?

Thanks-
E
 
Just go with the potassium. The potassium in powder form is twice as strong as the sodium but not double the price. Potassium is better for the body than sodium. No choice really. Most everyone prefers the potassium so the sodium on the LHBS shelf will be older and not as potent.

Forrest
 
Can anyone explain me the diferences between sodium bisulfite NaHSO3 and sodium metabisulfite, Na2S2O5.? Besides, which of these should I use in order to prolong the shelf life of my wine as well as avoiding oxidation?
 
Can anyone explain me the diferences between sodium bisulfite NaHSO3 and sodium metabisulfite, Na2S2O5.? Besides, which of these should I use in order to prolong the shelf life of my wine as well as avoiding oxidation?

They are the same thing. Well, sort of. Once you put sodium bisulfite into a solution of water, they both are sodium metabisulfite.

I've never seen sodium bisulfite in a homebrew store, though. I always see campden tablets, potassium metabisulfite (powder), or sodium metabisulfite (powder).
 
Make sure you have very small measuring spoons! My smallest is 1/8 teaspoon, and I found I had trouble with the small amounts. I started just buying the campden tablets instead, since it was easier for me. I don't use sulfites for sanitizing, although I used to. I brew beer too, so I use the same no-rinse sanitizer on all of my equipment. I use sulfites in all of my wines, to help preserve them and minimize any oxidation risks.
 
I found this handy little wooden measuring device when I first started in the hobyy and it's saved me quite a bit over the years since the powdered K and Na meta is much cheaper than campden tablets. I thin EC Kraus still sells them.

IMG_1050.JPG
 
Thank you both

i will definitely follow your both recomendations.

Besides, according to your experience, if i use the exact amount of sulfite( 1/16 teaspoon per each gallon of wine) at bottling how long could be the wines shelf life??
 
The difference between pms and sms is slight, I think pms gives you 56% sutphite and sms 60% sulphite so sms is slightly stronger.
You can get little electronic scales quite cheap on ebay, you can work out exactly how much to add by using the volume times the weight / .56
eg for 10 litre at 50ppm(0.000050) you need 500mg /.56 = 892mg. That is for pms. Remember 1 g/L = 1000ppm.
Isn't the metric system wonderful.
 
Thank you both

i will definitely follow your both recomendations.

Besides, according to your experience, if i use the exact amount of sulfite( 1/16 teaspoon per each gallon of wine) at bottling how long could be the wines shelf life??

A long time. It disapates with time, but depending on other factors (like the ABV, storage conditions, good corks), it can easily last years.
 
thank you, but i am a little confused due to your answer

What do you mean with " it disapates with time" what exactly disapates with time??does it mean that after bottling the wine is undrinkable because of the smell or the flavor??? or is the efect of the antioxidant the one that disapates?
 
thank you, but i am a little confused due to your answer

What do you mean with " it disapates with time" what exactly disapates with time??does it mean that after bottling the wine is undrinkable because of the smell or the flavor??? or is the efect of the antioxidant the one that disapates?

The SO2 dissipates with time. It will protect for a very long time, though, since the wine is corked and it will dissipate very slowly.
 
what about if i decide to treat the wine with so2 before bottling and keep some of the wine previously treated to taste it inmediatly? will be dangerous? will the so2 perceptible in taste or odor? is there a minimum of days to wait after bottling with so2 before drinking it?
 
The so2 doesn't really dissipate, it gets bound to compounds in the wine and becomes less effective. Some things that bind so2 are peroxide, pigments and acetaldehyde from oxidation. If your wine is "white" the so2 will last a lot longer. In terms of toxicity it doesn't change the "total bound and unbound so2" which is what matters to health, the total amount you add through all the rackings does matter. Try to keep the total under 200ppm or it will affect the taste and headache potential.
 
thank you gregbathurst,

so, let me understand!! are you saying that so2 it is not perceptible at taste or smell no matter if I just added seconds ago??
 
thank you gregbathurst,

so, let me understand!! are you saying that so2 it is not perceptible at taste or smell no matter if I just added seconds ago??

That's not been my experience. I can definitely taste and smell it, so I like to wait a bit. Generally speaking, if you keep it under 50 ppm, it should be under the discernible taste threshold but I can still smell a bit of sulfur in freshly bottled wines. If I'm going to be drinking it within a month or two, I don't sulfite those bottles.
 
It does take a while for additions to settle into the wine, not sure of the chemistry there. If you add it to a red wine you see a bleached area where the so2 is added, that is a reversable process which settles down. The whole thing also depends a lot on the pH of the wine, that is why you add acids like tartaric.
Different people also have variable sensory perceptions of so2, like other smells such as cork taint or brett.
 
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