Campden Tablets

[hypnoticmonkey]

CTs confuse me.

You add them to your must before pitching yeast to preserve the must.

Then you pitch the yeast, and it ferments.

But you can also add them to a wine to halt fermentation?

And I read today somebody saying that you can add a CT to a cider before priming and bottling it, to preserve it but still allow secondary fermentation.

So do they stop yeasties working or don't they?

 

[Alan Clark]

They will take out most wild yeast strains but the brewing yeasts are only slowed down by it, to stop a ferment you use Potassium Sorbate, not that my last attempt seemed to work too well.

 

I once grossly overdosed a real apple cider with over 1500 ppm SO2! (over 30 CTs per gallon)
Of course the yeast wouldn't work at this level.
When the SO2 dissipated out to between 450 and 500 ppm the yeast began working. (9 to 10 CTs per gallon)
The normal preservative level is 50 ppm. (1 CT per gallon)

 

[Samarith]

CTs temporarily stun commericial yeasts, so you can add 1 per gallon anytime you rack or bottle to prevent oxidation and infection by wild yeasts/bacteria.

After 24 hours or so the effects dissipate and the commercial yeast will get back to work.