how to use campden

[Vjuga]

Hello!

Ive a question about using campden/sulfite.
Im reading a lot here about it on the forum, but some things are still a bit unclear.
Some people say its just used for the purpose anti-oxydation, others say it kills unwated strains of yeast and germs.

Does Campden/sulfite kill yeast? If it does. Doesnt it stop your fermentation process?
When would you want to add it? Primary/secundairy or at bottling time?
I did choose to backsugar at bottlingtime for carbonation.

Thanks in advance.

 

[lumpher]

I sometimes use it when making wine. I'll add 1 per gallon of must (5 for a 5 gallon batch) at the start to kill wild yeast. I leave it soaking for about 24 hours. After that, I start turning it into wine. I also use 1 tablet (just 1; not 1 per gallon) just before racking (bottling) the wine so I can backsweeten it. I let it sit a couple days to let the campden do it's magic, backsweeten it, then bottle it.

I usually use Potassium Metabisulfite and Potassium Sulfate, though. I feel more comfortable using both, as 1 kills most of the yeast, and the other stops the few survivors from replicating.

 

[D the Catastrophist]

Cambden does not kill the wine yeast, or at least not at a level that interferes with fermentation. It does kill some of the unwanted bacteria on fruit, and I have found for making cider helps prevent the white film that sometimes forms. All you do is take 1 tablet (per gallon) crush it and add to your primary bucket when mixing everything at the start. Then before bottling, crush and mix in 1 more.

 

[Chalkyt]

I understand that it performs all three of the functions you mentioned. i.e. kills unwanted strains of yeasts (natural, which are a bit weak compared with "commercial" yeasts) as well as germs and bacteria, is an antioxidant which helps prevent oxidation of the cider, and can be a cure for some "cider ills" caused by bacteria and fungus.

Campden tablets are usually made of potassium metabisulphite (S02) and give a dose of 50ppm per US gallon. They are hard to dissolve and need crushing first, but are a convenient way to deliver the dose.

Claude Jolicoeur has a good discussion on the subject (Ch 14.1 in his book). I use a 5% stock solution such that 1ml per litre is 50ppm. This lets me dose my cider according to how big the batch is. The sulphite dissipates after 24 hours or so but protects the cider from pathogens until the alcohol level protection starts to build up after the yeast is pitched. I understand that juice with a pH greater than 3.8 will need some protection because there isn't enough acid to inhibit any bad bacteria.

I am afraid that I use it on a "monkey see, monkey do" basis without really understanding the process, but I never seem to have any problems so I assume it works. Other with greater biochemical knowledge than me might be able to contribute more.

 

[jtgoral]

I use one tablet per 5 gallon batch of beer before adding malt/grains.