Potassium Metabisulfite Question

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rebusify

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So if one campden tablet is 1/4 teaspoon of Potassium Metabisulfite and the instructions call for one campden tablet per gallon of wine then why does the instructions for Potassium Metabisulfite call for 1/4 teaspoon per 5 gallons of wine? Aren't they the same thing? Doesn't make sense.
 
So if one campden tablet is 1/4 teaspoon of Potassium Metabisulfite and the instructions call for one campden tablet per gallon of wine then why does the instructions for Potassium Metabisulfite call for 1/4 teaspoon per 5 gallons of wine? Aren't they the same thing? Doesn't make sense.
As @cmason1957 said, one campden tablet will dose the wine with 50-60ppm of sulfites. See this wiki for more info. However, the question is what dose of sulfites are you looking to add to the wine? The amount of free sulfites you should maintain in your wine depends on the pH. Graph seen here. At different stages of making your wine, you'll need to add or top up the sulfites. This does not mean you need to add a whole campden tablet per gallon each time. If you have the means of measuring the sulfites and the pH then that is your best way to make informed additions. Otherwise, it is safe to add a 1/4tsp of kmeta or a campden tablet on a 5-gallon batch at each racking to simply top up the sulfites.
 
QUESTION:

I made the FREE & TOTAL So2 analysis for my 'Merlot' wine

Free So2 - 19.2 | EU standart 20 - 30 mg/lit
Total So2 - 36.48 | EU standart 210 mg/lit


How to calculate how much metabisulphite to add to keep wine protected ?

I have 3500 liters of wine...
 
Sorry if this seems a bit harsh. I think the question was asked more generically, than specifically. This user doesn't need to know PPM of anything, just 1/4 tsp, 1/8 tsp, a full tsp! We don't need to know the minute details of the chemistry of wine, to make wine. I'm sure you are all well respected in you're fields, but I don't need to hear it at every turn, it doesn't help most (if any) users.
 
I just started to make wine as regular... so need need a little help.. where to find..
 
Where to find anything depends on where you are. In North America, there are many local shops, plus internet sources. Other parts of the world vary a lot. A search for local vendors is the first step, and after that search for sites that will ship to your country.
 
over about 35 years of making wine I ran the whole gammit in SO2 measurement I employed each new test technique or equipment as it became available.
one year I did extensive testing of SO2 to insure proper levels. I found that all that testing did not do any more benefit than the old dosage of 1/4 tsp per 5 gallons every three months. I have since removed any test equipment for so2 from my test equipment list. I have had no problems .
 
I don't use SO2 testing, either. 1/4 tsp per 5/6 gallons at every racking after fermentation, and every 3 months during bulk aging.

SO2 works by binding to contaminants, so it gets used up, depending on the level of contaminants, including O2. My goal is to ensure there is SO2 available when it's needed.

There is nothing wrong with SO2 testing; I simply don't find value in it.
 
I just started to make wine as regular... so need need a little help.. where to find..
That's a lot of wine for a beginner. A quick calculation would be about 46 tsp. based on 1/4 tsp per 5 gallons. Feel free to correct me if I'm wrong. I did this on the fly.
 
I don't use SO2 testing, either. 1/4 tsp per 5/6 gallons at every racking after fermentation, and every 3 months during bulk aging.

SO2 works by binding to contaminants, so it gets used up, depending on the level of contaminants, including O2. My goal is to ensure there is SO2 available when it's needed.

There is nothing wrong with SO2 testing; I simply don't find value in it.
I have some of my wine in bulk now and would rather not rack every three months. Can I simply add 1/4 tsp of k meta directly into the carboy?
 
I have some of my wine in bulk now and would rather not rack every three months. Can I simply add 1/4 tsp of k meta directly into the carboy?
To answer your question, yes you can.
I add potassium metabisulfite straight to my bulk aging wine every 3 months. Then take my drill and wand stirring attachment and stir for a minute or so. You can also stir it with the narrow end of a long wine mixing spoon.
Hope this helps.
 
To answer your question, yes you can.
I add potassium metabisulfite straight to my bulk aging wine every 3 months. Then take my drill and wand stirring attachment and stir for a minute or so. You can also stir it with the narrow end of a long wine mixing spoon.
Hope this helps.
Once in bulk I try to not disturb the wine. Why would you choose to churn things up.
 
Once in bulk I try to not disturb the wine. Why would you choose to churn things up.

To incorporate the k meta into the wine.
Would not racking every 3 months not churn the wine also?
I have found no ill effects of using the method that I stated on any of my wines that are bulk aging.
 
I have some of my wine in bulk now and would rather not rack every three months. Can I simply add 1/4 tsp of k meta directly into the carboy?
I do what @Rembee does, stirring gently.

Once in bulk I try to not disturb the wine. Why would you choose to churn things up.
Adding to Rembee's answer, wine does not have convection currents. If you simply dump the K-meta in, it will not distribute. You need to stir gently to make this happen.

I feel barrels on the other hand do require closer monitoring, especially when one doesn't rack every 3 months.
Why? One thing that comes to mind is the evaporation through the wood, but I can't see that affecting SO2, although that's a guess and not personal knowledge.

@rebusify, did we answer your question?

It's fascinating how a simple question can take on a life of its own and meander all over the place. 🙂
 

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