campden or potassium metabisulfite whats the diffrence?

[ace]

my brewshop today told me i could subsitute campden tabs for 1/8t potassium metabisulfite?(they were out) so what is the diffrence and should i break up and use only part of the tab for a 1gal mead?


any help would be apprecated!

 

[Rhianni]

I believe that 1 campden tablet has "about" 1/8 tsp of sulfite in it plus some other inert ingrediants in them to make it solid and a bit easier to handle.
My LHBS told me the same. They were out of campdens and sold me a bag of sulfite.

So far from experiance though 1/8th seems to be a little more then 1 campden. I am going 100% by taste of the finished product so it is by no means scientific. It just seems that it is leaving more sulfite flavor. I think they say 1/8th because its the smallest common measuring spoon.

 

[Oskaar]

The primary difference between Campden tablets and powdered K-Metabisulphit is that Campden tablets are Sodium Metabisulphit as opposed to potassium metabisulphite (powdered form available at your LHBS)

Apart from that 1 campden tablet per gallon will add sulphite at a rate of 75 ppm. You're also adding sodium to your mead/wine when you use Campden tablets, which can become detectable by taste especially in white wine/mead. Depending on the amount of sulphites already present from your fermentation I prefer to use the powdered K Metabisulphite because it's more exact (since I'm weighing it out), it doesn't add sodium that may become detectable in the flavor, and the K Metabisulphite will help during cold stabilization (Tartaric acid will precipitate out and tartaric acid cystals will form) rather than during long term aging in the bottle or carboy.

When using either form of Sulphite you must use pH to determine the amount of sulphites you'll need to add to reach your target level. When I do add sulphite it's generally 30-35 ppm.

Hope that helps,

Oskaar

 

[Rhianni]

So roughly 1/16th a tsp or 1/2 a campden per gallon. I had a feeling I was oversulfiting. I have several 1 gallon jugs that I plan to start doing some major testing and sulfite levels are one of them. I dont like testing with different batches at different times... to easy to have uncontrolled variables then doing them at the same time.

I probably should switch over to a weight based system instead of volume.

Thanks for the info Oskaar

 

[jaysbrew]

The primary difference between Campden tablets and powdered K-Metabisulphit is that Campden tablets are Sodium Metabisulphit as opposed to potassium metabisulphite (powdered form available at your LHBS)

Oskaar: actually, campden tablets may be sodium meta OR potassium meta. Nearly all homebrew shops carry the sodium type because they are a little cheaper. However some (like me!) sell potassium meta tablets because that's what most customers want to get. As you mentioned, the sodium meta can leave an unwanted flavor (and the TTB even forbids its use). Here's a link to the campden I sell:

http://jaysbrewing.com/catalog/product_info.php?cPath=29_56&products_id=276

Cheers,
Jay

PS: remember gotmead'ers - use 'gotmead' as a coupon code on my site and get 10% off + I'll donate 5% to the gotmead site.

 

[Oskaar]

Thanks Jay, good to know.

I've only ever seen the Na-Meta around here in SoCal.

Cheers,

Oskaar