# campden tablet, is this right?



## citizensnips

Just bought these campden tablets from the local brew shop. Everything I've read and seen doesn't suggest id need 8 of these tablets for 30L. I put the pen in for size reference, whats everyone's opinions? Packaging mistake or should I actually dump 8 of these bad boys in my water?


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## manticle

What are they for?


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## warra48

Campden tablets are used in brewing to reduce chlorine. This from Wikipeadia:

Campden tablet

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*Campden tablets* (potassium or sodium metabisulfite)[1] are a sulfur-based product that is used primarily in wine, cider and beer making to kill bacteria and to inhibit the growth of most wild yeast: this product is also used to eliminate both free chlorine, and the more stable form, chloramine, from water solutions (i.e., drinking water from municipal sources). Campden tablets allow the amateur brewer to easily measure small quantities of sodium metabisulfite, so it can be used to protect against wild yeast and bacteria without affecting flavour.
Typical use is one crushed Campden tablet per gallon of must or wort. This dosage contributes 67 ppm sulfur dioxide to the wort but the level of active sulfur dioxide diminishes rapidly as it reacts with chlorine and chloramine, and with aldehydes (particularly in wine). Therefore, the concentration of free sulfur dioxide is greatly diminished by the time the beer or wine is consumed. *However, when used only for the purpose of dechlorinating tap water before brewing, one tablet will effectively treat 20 gallons of water.*[2]
Campden tablets are also used as an anti-oxidizing agent when transferring wine between containers. The sodium metabisulfite in the campden tablets will trap oxygen that enters the wine, preventing it from doing any harm.
It is a common misconception that campden tablet can be used to halt the ferment process in wine before all the available sugars are converted by the yeast, hence controlling the amount of residual sweetness in the final product. This however is not true. In order to halt fermentation, enough campden tablets would have to be added to render the wine undrinkable. Alternatively, when used in conjunction with potassium sorbate, the yeast population will be greatly reduced and prevented from reproducing. Without the addition of potassium sorbate the yeast population will only be stunned and eventually repopulate if provided with enough fermentable sugars.[3]
Campden tablets typically contain 0.44 g each of sodium metabisulfite (plus filler) and 10 of these are equivalent to one level teaspoon of sodium metabisulfite. Other related substances are sodium/potassium sulfite/bisulfite. Further complicating the subject, each is also referred to interchangeably as—sulfites, and the 'bi' can be found as 'di'. In terms of usage, sodium thiosulfate is a closely related compound.
The name Campden tablet comes from the town of Chipping Campden in Gloucestershire, England, where the original solution was developed in the 1920s by the Fruit and Vegetable Preserving Research Station - now Campden BRI.[4] The idea was then taken up by the Boots Co., who developed the tablet.
Campden tablets are also useful in decontamination and neutralization after exposure to tear gas.[_citation needed_]
The molar mass (commonly called molecular weight or MW) of potassium metabisulfite is 222 grams per mole, while the molecular weight of sodium metabisulfite is 190 g/mol.




Note: Highlight in red is my edit. 
No way do you need to use 8 tablets in one hit to treat the quantitiy of water the OP talks about.


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## manticle

> Campden tablets are used in brewing to reduce chlorine.


This bit I get. They can also be used to inhibit other yeasts and bacteria in cider and winemaking while the preferred yeat innoculation dominates. However the OP location says Melbourne and you shouldn't need to dose Melbourne water with campden for brewing.


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## citizensnips

Im currently in barwon heads, the water he is treated with chloramine and campden is one way of getting rid of it without using a water filter. My question is to anyone that uses or knows about these I was under the impression one was more than enough, leading me to question using 8 of these for a single batch? I cant figure out if they're less potent than normal or its a labeling blunder?


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## manticle

Check the weight and percentage. 8 sounds like loads.

I remember now you posted a while back about Barwon water.


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## barls

1 per gallon is the dosage rate for wine.


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## manticle

Might help: http://morebeer.com/articles/removing_chloramines_from_water

Campden serves a different purpose in winemaking doesn't it barls?


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## barls

yep. its used to ether sterilise or stabilise the wine depending on when its used.


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## citizensnips

manticle said:


> Check the wright and percentage. 8 sounds like loads.
> 
> I remember now you posted a while back about Barwon water.


Yeah I was wondering if you remembered, you gave me a wealth of good info, cheers again for that



barls said:


> 1 per gallon is the dosage rate for wine.


Barls would you happen to know then the recommendation for beer?

I found this also which is specifically in relation to beer 'You should need half or less of a Campden tablet to treat 10 gallons of water. If you find you are needing more you are probably doing something wrong as 1 typical tablet will treat 20 gal of water chloraminated (no free chlorine - this is the worst case) to 3 mg/L free chlorine equivalent. This depends somewhat on the weight of the metabite in the Campden tablet and whether the salt is potassium or sodium metabisulfite. If Campden tablets are not available from your LHBS or by mail order you can use potassium (or sodium) metabisulfite available from wine making hobby suppliers. Doses are given in the table below.'
Suggesting one tablet is enough for roughly 75L, was from http://www.homebrewtalk.com/f128/campden-tablets-sulfites-brewing-water-361073/

Don't think I'll be using more than 1-2 either way


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## manticle

Check the morebeer link I posted for dosage rate.


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## Blind Dog

I'm pretty certain Warra's post answers most questions on use in brewing - *However, when used only for the purpose of dechlorinating tap water before brewing, one tablet will effectively treat 20 gallons of water*



I use it (most of a tablet crushed into the mash water, the rest of that tablet for the sparge water if I’m sparging) to deal with chloramine and any chlorine that may get through the filter. Per Sydney Water, it is common practice to regularly flush higher than normal doses of chlorine, typically after heavy rains or coming into summer, through the system. 

I’ve seen people say that it can help reduce oxidisation in the mash and to inhibit wild yeast. I’ve never seen any evidence to support either, but then I’ve not really looked. It may simply be an inference from its use in wine making.


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## Blind Dog

Which everybody else had already said in one way or another (took me two hours to post!)

I'll get my coat...


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## citizensnips

Sorry Warra I was on my phone and didn't read over the entire article. All good, thanks for input and clarification all.
Half a tablet or so it is.
Cheers all


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## barls

citizensnips said:


> Yeah I was wondering if you remembered, you gave me a wealth of good info, cheers again for that
> 
> 
> Barls would you happen to know then the recommendation for beer?
> 
> I found this also which is specifically in relation to beer 'You should need half or less of a Campden tablet to treat 10 gallons of water. If you find you are needing more you are probably doing something wrong as 1 typical tablet will treat 20 gal of water chloraminated (no free chlorine - this is the worst case) to 3 mg/L free chlorine equivalent. This depends somewhat on the weight of the metabite in the Campden tablet and whether the salt is potassium or sodium metabisulfite. If Campden tablets are not available from your LHBS or by mail order you can use potassium (or sodium) metabisulfite available from wine making hobby suppliers. Doses are given in the table below.'
> Suggesting one tablet is enough for roughly 75L, was from http://www.homebrewtalk.com/f128/campden-tablets-sulfites-brewing-water-361073/
> 
> Don't think I'll be using more than 1-2 either way


off the top of my head cant remember what a tablet is equivalent to in potassium metabisulfate. 
i vaguely remember it being about .5 of a gram in a tablet but its been a fair few years since ive had to figure it out.
stay away from the sodium metabisulfate as its the one more people have a reaction with.


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## Bribie G

It's in a lot of cheap wines such as Golden Gate Spumante, passion pop etc and probably most cask wines .. they have to put it on the label as preservative 223. Also related are sulphur dioxide 220 (the gas that is released by Sod Met) and several others.


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## manticle

In a lot of expensive wines too.


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## barls

Bribie G said:


> It's in a lot of cheap wines such as Golden Gate Spumante, passion pop etc and probably most cask wines .. they have to put it on the label as preservative 223. Also related are sulphur dioxide 220 (the gas that is released by Sod Met) and several others.


actually they are 220 and 222. 220 being the sodium version and 222 being the potasium version and just about all wines use either but its higher in the cheaper and casks.


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## joshuahardie

In my area (Gosford) I can taste/smell the chlorine in the water, and I use 1 tablet crushed in my mash water


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## 1974Alby

> Im currently in barwon heads, the water he is treated with chloramine and campden is one way of getting rid of it without using a water filter. My question is to anyone that uses or knows about these I was under the impression one was more than enough, leading me to question using 8 of these for a single batch? I cant figure out if they're less potent than normal or its a labeling blunder?



based on this and Manticle's comments, are you suggesting that you dont need to use campden tabs to treat chlorine only? (and that it is beneficial when chlormaines are present?)


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## HBHB

Keep in mind that free gases is what you smell when the water's running. That's what is not in the water.

Here's a paper that discusses use of "Campden" to dechlorinate by sulphonation.

http://water.epa.gov/scitech/wastetech/upload/2002_06_28_mtb_dechlorination.pdf


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