K-meta and sulfur dioxide

I hope this is the right group to pose this question.
Wine makers routinely add K-meta to their must to ensure that all bacteria and wild yeast in the fruit (or juice ) is incapacitated 24 hours before pitching yeast. Brewers don't seem to use SO2 in this way and so the need to chill the boiling wort rapidly to enable the yeast to be pitched before there is any opportunity for the wort to be infected is the result. Is there a reason that K-meta is not used by brewers? Are the bacteria in the grain immune to the effects of SO2? Vintners would say that for all intents and purposes all the free SO2 will evaporate off soon enough to allow the pitched yeast to bud and reproduce without any untoward effect. Is there something different about brewing that precludes the use of Potassium Metabisulfite? Thanks

There is no need for it. Wort is boiled long enough to kill off any bacteria that could compete with the yeast and after rapid chilling (which is done for DMS control as much as anything else) a good pitch healthy yeast into properly oxygenated wort will result in a rapid drop in wort pH and a rapidly rising yeast population. Other bugs don't stand a chance.

I suppose we could say that in wine making we need to do something to incapacitate if not kill wild bacteria in order to insure that the desired yeast strain can dominate and use SO2 for this purpose. In brewing the boil does this.

OK but the point at which brewers say that their wort is most susceptible to infection is when the wort is cooling - hence the need for speed and so the need for vast quantities of cold water to transport the heat from the wort. My question is IF K-meta can inhibit the growth of wild yeast and bacteria then I can allow the wort to cool at its own rate and not need to waste water. Those who use the no chill technique don't seem to worry about excessive DMS - or at least no one seems to invoke this as a practical weakness of this technique. Is rapid cooling needed to inhibit the production of DMS even if the grain is barley and not wheat?

bernardsmith said:

OK but the point at which brewers say that their wort is most susceptible to infection is when the wort is cooling - hence the need for speed and so the need for vast quantities of cold water to transport the heat from the wort. My question is IF K-meta can inhibit the growth of wild yeast and bacteria then I can allow the wort to cool at its own rate and not need to waste water. Those who use the no chill technique don't seem to worry about excessive DMS - or at least no one seems to invoke this as a practical weakness of this technique. Is rapid cooling needed to inhibit the production of DMS even if the grain is barley and not wheat?

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If S02 is added to hot wort, it will dissipate (or even neutralize?) quickly.

Many brewers do "no chill" brewing without any infection issues. DMS may occur, but no chill brewers seem to not have a problem with DMS either.

K-meta is pretty much needed only for no-boil type of fermentations, like in cider making from fresh apples, or for fruit wine musts.

Note that some brewers do add metabite to wort but for its reducing potential, not its biostatic potential.