campden tablets

[LewisA]

Hello just a quick question regarding campden tablets

I used half a campden tablet per gallon of water to dechlorinate it (I used a whole tablet because it was 2 gallons). However I read in a recipe that you need to add another one when clearing with wine finings. This would give me overall, one and a half campden per gallon of wine? (If I make a gallon of wine)

Do you even need to add a tablet when clearing using finings? And if so will that be too much campden or is it acceptable because I read somewhere anymore than one tablet per gallon was too much?

Many thanks
Lewis

 

[Chelstonbrewery]

It has always been recommended that one uses a camden tablet every time one racks off the wine. This serves two purposes - the sulphur dioxide released neutralises any oxygen picked up during racking and guards againgst any infections and wild yeasts. If using Potassium Sorbate to stop the fermentation, a camden tablet must be used or one will have a wine smelling and tasting of geraniums.

 

[Moley]

Hang on, let's see if I can break this into bite size pieces :wha:
(edit: although I see that Chelston has covered most of it already)

If you're brewing beer, half a CT is good for dechlorinating 5 gallons.

If you're making wine from fresh fruits, flowers etc. then EITHER boiling water OR one CT to the gallon is used to knock out wild yeasts.

I never bother with pre-treating water for things like juice wines as metabisulphite in one form or another is always going to be added sooner or later.

You should be using one CT (or equivalent) per gallon whenever racking to guard against infection and act as an antioxidant. If you're stabilising with potassium sorbate then you MUST use that in conjunction with campden. As finings are usually added after racking, the two usually go together.

Most of my wines will get 2 CTs (or equivalent) over the course of 1st and 2nd racking, or 1st racking and filtering. Some long-term wines (6-12 months or longer) might even get three. It does dissipate with time.

 

[LewisA]

Thanks Guys for clearing up a fair few questions :)

So for a tea wine using standard tap water, would you say it was wrong to have added half a CT?

 

[Moley]

No, I wouldn't say it was wrong, it certainly can't do any harm but might mean that it takes your yeasties a little while longer to get established.


Of course, I don't know where you are or what your tap water tastes like, ours is pretty good but if I lived just 10 miles away near my place of employment I would use bottled water or treat with everything at my disposal.

 

[evanvine]

Ade, do you not think that adding a Campden tablet at every operation will end up ODing?

 

[Moley]

Depends on how many operations over what period of time.

With something like a juice wine, mine gets racked and fined around 4 weeks and filtered around weeks 5-6, then left in bulk for a further 3 months before bottling (no further sulphite added on bottling).

With something like an elderberry wine it will get racked around 1 month, 3 months and 6 months, and then given at least another 6 months before bottling.

To what extent does it persist in the finished product?

On a country wine cold start you might use one CT (or equivalent) per gallon to knock off the wild yeasties before pitching your own after 24 hours, so that would suggest it's a quick fix but its effects soon wear off.

 

[evanvine]

To what extent does it persist in the finished product?

That’s a difficult one to answer; you really need to measure the SO2 level.
I only have experience with wine from grapes and real cider.
In both cases, prior to crushing, you need to spray the fruit with SO2 solution.
This is more to prevent oxygen discolouring the juice, but it does knock wild yeast on the head.
Just before bottling, the SO2 level is measured (yes there is still 20-30% left) and adjusted to 50mg/ltr.
As I understand it, 50mg/ltr is the minimum level for preservation and the maximum level to prevent it being tasted.

A few years ago, I accidentally sprayed my fruit with a 10% SO2 solution rather than a 1 % solution; the result was an SO2 concentration of over 1000mg/ltr.
It took over a month, vented to atmosphere, before the yeast started working (SO2 450mg/ltr).
When it came to bottling, the SO2 was still 150mg/ltr; it was not pleasant to drink!

Info: One CT will impart 50mg/ltr when disolved in 1 gallon (sorry about mixed units).