Strange K-Meta behavior

[ibglowin]

I received a new 1lb bag of K-Meta a few weeks back. Its from Crosby Baker and has the new label so I know its not old plus it came from George!

Anyways I mixed my first gallon of sanitizer solution from this stuff and noticed right away that it just does not have the same amount of volatile SO2. I even waited 3-4 days and then used it to sanitize a carboy. Poured the usual 20 oz or so in and shook the carboy up with a stopper on it. Let sit for 5 min, come back take a good whiff and nothing. Just barely a hint of SO2 and a LONG way from the usual knock your socks off level that I got on my previous bag.

I decided to test it last night (surprise!) I set up the Aeration/Oxidation rig. My set up calls for a 20ml sample. I took 2ml of the prepared 1 gallon sanitizing solution and then diluted that 10X. I analyzed that sample as normal and got approx 7600ppm free SO2.

The Crosby Baker K-Meta list 1/8 tsp = 100ppm Free SO2 in solution. I used 50 gms so that theoretically comes out to ~8400 ppm Free SO2. My scale is (+/-) 1.0 gram so not all that accurate. Combine the possible dilution factor error and I feel pretty confident that this stuff does indeed have plenty of SO2 in it but for some reason it just does not volatilize like it should.

Seems like this would be fine for addition to wine but I am wondering about its effectiveness in sanitizing things like carboys, corks, tubing where you are counting on the SO2 gas to basically volatilize and kill any bad actors.

I may try and find a different brand at a LHBS next time I get a chance to compare. Perhaps they changed the formulation some how but it just seems like a strange phenomenon at this point.

Anyone else seeing this in their K-Meta using the "Nose Factor" test?

 

[Flem]

Mike, I'd be interested in knowing the results of the "sniff" test on your carboy today. The last time I mixed up a gallon of solution, I couldn't smell anything until I took some out of the jug. Once there was head space in the jug I had plenty of gas smell. My rationale was that there wasn't enough space for the gas to accumulate until I poured some of the solution out. I used the same Crosby Baker you were using. Just my experience. Mike

 

[ibglowin]

I will give it another test in a few days. Will be bottling this weekend. George talked with Crosby and they claim the lack of strong odor is not an indication of a lack of effectiveness.....

Hmmmm OK......


Still not feeling overly secure in this bag of K-Meta but guess I will proceed as usual and look for another source to compare it against down the road at some point.

 

[Randoneur]

This is how I would test it. Put some in a bucket and put a bag over the bucket, come back in a half hour, lift the bag and see if it gassed out into the head space.

 

[BobF]

For sanitizing I always add 2 tsp citric acid to lower the pH of the solution which increases volatility.

The nose test has always given widely different results for me even from the same package of k-meta.

I periodically run an A/O on my solutions just to make sure everything is OK - never had lower levels than expected regardless of nose test results.

 

[Arne]

I had kinda the same problem.Mixed the solution up in a 2L. pop bottle. Cautiously took a sniff, nuthin. Decided to use some of it anyway. Put some in a gal. carboy, put my hand over the opening and shook it around. Poured it out, no oder or very little. Got my hand up by my face and could smell it on my hand. Had the same thing happen with another carboy. Not sure why it is not offgassin strong out of the storage bottle, but am going to check it later on today. Not very scientific, but the nose test usually works for me. Arne.