Has anyone compared SO2 additions via KMBS solution to those from a 6% straight SO2 solution made from bubbling SO2 gas or liquid SO2? I have found that an 11.5% solution (%SO2) made from KMBS is much less noxious to deal with than a 6% solution made from bubbling SO2 gas through water–and my free SO2s stay where I want them. In that case, then, might the addition of KMBS has less of a sensory impact on the wine than the equivalent addition of pure SO2? Has anyone done a side-by-side trial?
Depends on where I’m making the addition.
Ive never made a KMBS solution to add unless it is to a tank. And for liquid adds, I’ve always just bought 6% from the welding company. Ive never wanted to expose my employees to the off-gassing of making my own liquid. My guess with the KMBS solution at 11% is does that solution STAY at 11% over time? And also if your are going to do a liquid add anway and you can avoid adding the potassium to the wine from the KMBS I’d prefer not to.
For barrels, I’m a big believer in taking those same SO2 kegs with a doser and making a liquid add straight before topping. The other preferred method is the effervescent KMBS packets. Either way, those decisions are based more on cellar worker comfort/safety than precision in dosing the SO2 - but then again, is precision REALLY that important… As long as im within 5ppm of my target I’m okay.
We used to use the 6% liquid SO2 from the Welding company but it is nasty to use (and make!), so I’ve gone back to KMBS. A 12% KMBS solution doesn’t seem to be as harsh to me, and I find the additions get the free SO2 to where we want it. The 6% liquid would sometimes not get us to the free SO2 we were looking for and require another add.
The 12% solution does degrade over time to ~ 6% so we make it fresh and use it all up.
-Bryan
ITB-Alderbrook Winery
I make a 10% solution for bbls, and for tanks I just weight KMS as needed and dilute that and add.
Used to use the 6%, then started wondering what the heck I was paying for when I could make and use a 10% solution for a whole lot cheaper.
To your point, Matt, I cannot think of any reason why bubbling gas and dissolving metabi would be different other than the associated addition of cations with metabi…but still, I am not sure how that would affect the “stickiness” of frees.