potassium metabisulfate vs. sodium metabisulfate

The one that has "sodium" in its name just suffers from mass hysteria. You know - fried foods, sugar, caffeine, SALT, etc..

Yes, but you're much better off using a dilute solution of "clorox" bleach.

Potassium ions isn your wine are much better than sodium.

I use 100 ppm 12-24 hours before adding yeast, then I add no more.

vince norris

Sorry, but you have those reversed. Sodium metabisulfite is 67% available SO2 and potassium metabisulfite is 58% (available SO2). Of course, that assumes pure chemical, which neither ever is. You're doing well to get 50% out of the potassium salt, even from freshly purchased stuff, because it is so reactive to oxygen in the air - especially in high humidity conditions. That's why the pros recommend buying it fresh every year from a known, good source.

Although the amount of added sodium from additions of sodium metabisulfite is minimal in the finished wine, purists always use the potassium salt - partly because the excess potassium will drop out during cold stabilization. Any added sodium remains in the finished wine. Whether or not it imparts any discernable saltiness to the wine is moot.

Also, the part about killer yeast is arguable. Lots of the pros use EC-1118, but there are valid reasons to not use it, based mostly on style. If you want a long, slow fermentation, or are making a wine that you want to stop short of dryness, or are running ML concurrently with the primary fermentation you _don't_ want to use EC-1118. That's why there are so many different yeast strains on the market. Each of them has different properties. All that said though, EC-1118 is a very good general purpose yeast that tends to yield clean fermentations that don't stick.

BTW, just to set the nomenclature straight, it's metabisulf_i_te; not metabisulf_a_te. Those are different oxidation states. I'm not even sure the metabisulfate exists. The metabisulfite probably oxidizes to sulfate.

Tom S

Indeed, no sensible winemakers would deliberately add chlorine to wine. But, chlorine is extensively used in many wineries to sanitize equipment. The only precaution needed is to rinse away _all_ of the chlorine.

Adding to what Lum said, chlorine actually *is* fairly commonly used in wineries; it is simply rinsed off very well afterwards. Where chlorine is *not* used is on porous surfaces like barrels where it can not be rinsed off.

I think most of us are violently agreeing here - the statement was that chlorine is *never* used as a sanitizer in wineries and a few of us pointed out that's not the case. Since you say "most" don't use it in Australia, I'd guess there must be some that do. I would say

- Mark W.