8 replies to this topic

[Bart]

Does meta go bad or lose its power after a couple years?

I have some dry powder that I just mixed up to do a little cleaning and the solution had no smell at all. Is this normal? From my possibly fuzzy memory, I thought the mixed solution had a very strong chemical smell.

Am I getting my chemicals confused or did I not add enough powder or is something else happening?

Thanks!
Bart

[Joe_Sallo]

Yes, it goes bad as it is exposed to air. I replace mine for winemaking yearly. The old stuff, i use for sanitizer like you are doing but if it has no smell it's not doing anything for you. It should smell gawd awful. Remeber to add a little acid if you are using it as a sanitizer, the lower the pH the more effective it is. By the way, you should not just sniff at this stuff, you should waft it into you nose.

I use 1/4 teaspoon of k meta and 1/2 teaspoon of citric acid pr quart.

[Calamity Cellars]

I buy mine from morewine and it comes in a nice metallic ziplock bag. I used it for two years and saw no degradation in strength. I was very meticulous about squeezing the air out and getting it zipped up immediately after every use. However, as Joe said, it does degrade in strength and a good rule of thumb would be....if in doubt, throw it out. It's cheap.

[Bart]

Thanks guys!

Joe - your formula "1/4 teaspoon meta and 1/2 teaspoon of citric acid per quart" is for a sanitation solution, correct?


Thanks again,
Bart

[Proud Puppy]

As it is a sanitizing solution and I apply with a spray applicator, I tend to use a high dose. I use roughly a Tablespoon pre liter with a round a teaspoon or so of tartaric acid to lower pH. The directions on one brand was 2 ounces in a gallon which was half of the fist sized 4 oz bottle. I think that this is a close estimate of that dose.

The 2Oz per Gallon is around 15 gm PER LITER and at 57 % weight SO2 this gives roughly(edit )10000 mili gm per liter which is 10000 ppm roughly.(65% is 10000, 57% is 8500 more precisely , as noted below.)

A teaspoon is roughly 5 grams or so and 3 tsp or 1 Tbsp is 15 grams and is the same per liter in a rough approximation.(edit) as 8500 ppm or around 10000 ppm ballpark

Edited by Proud Puppy, 18 September 2011 - 12:11 AM.

[running wolf]

Yes Meta does go bad over time. As said above replace after one year and sorbate every six months. I do continue to use the meta for sanitizing using three teaspoons per gallon and also add about half that much of citric acid.

[gregorio]

As it is a sanitizing solution and I apply with a spray applicator, I tend to use a high dose. I use roughly a Tablespoon pre liter with a round a teaspoon or so of tartaric acid to lower pH. The directions on one brand was 2 ounces in a gallon which was half of the fist sized 4 oz bottle. I think that this is a close estimate of that dose.

The 2Oz per Gallon is around 15 gm PER LITER and at 57 % weight SO2 this gives roughly 1000 mili gm per liter which is 1000 ppm roughly.

A teaspoon is roughly 5 grams or so and 3 tsp or 1 Tbsp is 15 grams and is the same per liter in a rough approximation.

2 ounces per gallon is roughly 8.5 grams per liter or 8500ppm.

1 ounce = 28.4 grams
1 gallon = 3.8 liters
1 gram per liter = 1000ppm

2 ounces Potassium Metabisulfite * 28.4 = 56.8 grams
56.8 * 57% = 32.4 grams pure SO2
32.4 / 3.8 liters per gallon = 8.5 grams SO2 per liter
8.5 grams * 1000 = 8500ppm

No?

[Proud Puppy]

OOps, cought speeding again... funny how 2/3 of 15000 goes to 1000 not 10000 . Thie sanitizing is strong, but it does get drained or quickly wiped, and is the usage widely mentioned. I just eyeball the sanitizing, but additions are double and triple checked. Good catch. Wanna buy an extra zero? Post edited to reflect the correct math guestimates!

This is a widely used sanitizing dose , printed on many bottles. Some say 1-2 Oz per gal, some say 2 oz per gal. I have seen lesser recommended dose usage but I have used this amount for a long time.

I think 1000 ppm is a little on the low side for sanitizing, even with a low pH no? 1/4 tsp per liter just seems weak.

[ReUnitePangea]

As it gets older and exposed to air and moisture it'll get hard and clump. I worked in a winery that I had to break the Kmeta up with a hammer. They buy it in 25kg bags and dont want it to go to waste. I keep mine in a tupperware or mason jars. For cleaning I dont really care how old it is as long as it smells like kmeta. For wine add's I'll buy a kilo in the summer so its nice and fresh.

I also freestyle my sanitizing solutions usually on the extra strong side.