Campden tablets

[DannyW]

Thanks guys, I've only just come out of the cupboard from crying about being ignored

I have a second FV I try that method on my next brew. I've done a few brews with tap water and a couple with tesco bottled so I can try this for a comparison

[Dr. Dextrin]

On a similar subject can anyone advise what quantity of campden to use in a five gallon batch to act as a preservative/preventative. I recall in one of Dave Lines book that sodium met is the only allowed preservative in commercial beer. Or will the natural qualities of hops and co2 be sufficient?

Sodium Met will act as a preservative to give you a better shelf life but it will also kill the yeast, so only advisable if you are force carbonating the beer rather than secondary ferment in a sealed vessel ( bottle/keg)

The hops also act as as a preservative also.

Ooops well thats a bit of a worry as both 40 pt fvs and two pbs have had 1/2 a tab added as i am of the belief that this warmer weather is more conducive to random infection... the ones in brew still took off quite well, but now i'm worried that the two in pb, which i use to condition before priming, wont have any viable yeast in to carbonate when i prime. Any suggestions or is it a prime it and see situation?

I once tried using Campden tabs in beer. I didn't have a problem with infection, but I wondered if the anti-oxidant property might make beer keep longer (it's the oxygen seeping through the plastic that hastens the demise of beer in pressure barrels). I used 3 tabs in 5 gallons, which is a bit less than the minimum rate normally used for wine (1 tab per gallon).

TBH, I didn't notice any difference in how long the beer lasted, nor in how well it carbonated (priming with sugar in the usual way). The only effect was a sulphury taste in the beer, not unlike the taste you sometimes get in draught Bass, say, but a bit stronger. Not particularly unpleasant, though. For some reason you never get that taste in wine, but beer seems to react differently.

Anyway, I never repeated the experiment as there seemed to be no benefit, unless you like a bit of sulphur and can't get it from the yeast.

[Hippo]

My last two brews are in the pressure barrel conditioning. In both the water was treated with 1/2 a crushed camden tab prior to mixing up. Beer is much better that before. No home brew taste. Only lovely beer taste

[MartinC]

I would like to clarify some misconceptions about Campden tablets and their use for killing microbes.

Campden tablets work by reacting with acids to release sulphur dioxide (SO2), this being the active sterilising agent. Normally, about 50 parts-per-million of SO2 will kill many, but not all, organisms. Cultured yeasts tend to be more tolerant of SO2. However, since acid is required for the release of SO2 then is follows that the more acidic (lower pH) the must/wort then the more SO2 will be released. So, for cider and things like rhubarb wine, one campden tablet per gallon is fine. Beer, however, has a pH in the 5s - acidic but not very much (pH is on a logarithmic scale so a pH of 2 is not 2 times more acidic than 4, but 200 times so). In this situation campden tablets would have to be added in quite large numbers per gallon to have any sterilising effect. Further, the SO2 that gets released can bind to various chemicals in the beer thus further reducing its effectiveness.

So, the amounts of campden tablets that have been suggested in this thread will have absolutely no sterilising effect whatsoever.

As for water treatment, I know nothing about those chemical reactions. It might be worth contacting your local water supplier directly to see what they think.

Cheers, Martin