Dosing fresh fruit with k. Meta? How much?

[CaptainPolish]

I make a 10% solution and for me it makes everything so much easier. 500 ml distilled water, 50 gr k-meta. You can scale up or down to suit your needs. I usually make 200 ml at a time. Warning - don't smell it. If you're curious, hold it a foot away from your nose. It'll knock your socks off. Freshly made solution doesn't smell much but after a couple hours - yikes!
Then you just need a cheap graduated syringe. There are tables listing how much to use. Basic dose I think is 3.3 ml per gallon but the amount actually needed depends on pH.

Does Kms have a half-life in water? or in a water solution does it go bad at some point? And I will defiantly look into that, I'm at a scale at the moment where I probably don't need to do a 50g solution yet, but like you said I can scale down
https://www.accuvin.com/wp-content/uploads/2015/04/How-SO2-and-pH-are-Linked.pdf not sure if its ok to post here, but is this a good guide? can I follow this for the mathy bits?

 

[BigDaveK]

Does Kms have a half-life in water? or in a water solution does it go bad at some point? And I will defiantly look into that, I'm at a scale at the moment where I probably don't need to do a 50g solution yet, but like you said I can scale down
https://www.accuvin.com/wp-content/uploads/2015/04/How-SO2-and-pH-are-Linked.pdf not sure if its ok to post here, but is this a good guide? can I follow this for the mathy bits?

I don't know how long it lasts which is why I make a smaller quantity. I generally make a new batch every 2ish months.

Here's another reference. Has a table to avoid some of the mathy stuff.

http://nanaimowinemakers.com/using-sulfite-so2-to-protect-wine-theme/

 

[winemaker81]

Does Kms have a half-life in water? or in a water solution does it go bad at some point?

I make a batch of K-meta solution for sanitizing roughly every 6 to 12 months: 1 gallon water, 2 Tbsp K-meta, 1 Tbsp acid (tartaric is supposedly best, but I'll use what I have the most of).

This gets used and re-used until the jug is half full (there are losses with usage) or it gets a significant amount of debris in it. Even at 12 months old the jug will reek of SO2, so I assume it's still good.

 

[Rice_Guy]

Back to the OP. From a food plant perspective, if I had an infection issue, I would first get the pH below 3.5. Bacteria will be out competed if if the growth conditions are more favorable for yeast and less favorable for bacteria. ,, My second control method would be to make the wine anaerobic ( put it under airlock) some place after 1/3 sugar loss and before 1.020 gravity.
From a technical point of view, if I dosed at 200ppm SO2 I probably would still have detectable bacterial plate count and it would taste like sucking on a match. ,,, Fermentations are a numbers game, the target organism ALWAYS has to out compete everything

 

[CaptainPolish]

I make a 10% solution and for me it makes everything so much easier. 500 ml distilled water, 50 gr k-meta. You can scale up or down to suit your needs. I usually make 200 ml at a time. Warning - don't smell it. If you're curious, hold it a foot away from your nose. It'll knock your socks off. Freshly made solution doesn't smell much but after a couple hours - yikes!
Then you just need a cheap graduated syringe. There are tables listing how much to use. Basic dose I think is 3.3 ml per gallon but the amount actually needed depends on pH.

Ok, plan on making a kmbs solution soon. Here is my thought, I would like to put it in a mason jar. Is that an issue with the metal lids? also the reason I would like to do this is that I have hundreds of spare sterilized ml syringes, I also made lids that have injection ports (from my liquid culture days). I am thinking of putting the solution in that as to keep it sanitized, and then I can pull whatever ml per gallon I would need from that. any concerns with this method?

 

[Raptor99]

Ok, plan on making a kmbs solution soon. Here is my thought, I would like to put it in a mason jar. Is that an issue with the metal lids? also the reason I would like to do this is that I have hundreds of spare sterilized ml syringes, I also made lids that have injection ports (from my liquid culture days). I am thinking of putting the solution in that as to keep it sanitized, and then I can pull whatever ml per gallon I would need from that. any concerns with this method?

I have tried that, and after a few weeks it will corrode the metal part of the lids. I think that the SO2 will condense and form sulfuric acid. There are some all-plastic lids from mayo jars that will also fit on mason jars. Some peanut butter jar lids will fit as well. No good for canning, but perfect for this purpose. That is what I use.

 

[CaptainPolish]

I have tried that, and after a few weeks it will corrode the metal part of the lids. I think that the SO2 will condense and form sulfuric acid. There are some all-plastic lids from mayo jars that will also fit on mason jars. Some peanut butter jar lids will fit as well. No good for canning, but perfect for this purpose. That is what I use.

thank you! exactly what I needed to know!

 

[Rice_Guy]

Metabisulphite is corrosive, I use a 1/2 gallon growler with a cork. The cork becomes black and hard over two years.

 

[Charles DeVier]

I use Star San to clean my wine making equipment. To sanitize fruits, I fill a 5 gallon bucket 1/2 full of water and add the recommended Star San. Then I add my fruit to the water mix and let set as I process each apple, pear, peach, etc. Star San is not poison, so no worry.