Campden or Purebrew during fermentation?

[Jiffy176]

Hi team.
My second attempt at an extract kit was a Coopers Mexican Cerveza. Its all bottled and some have been really good and others have got a real homebrew twang to them.
I get this may be my water as its hard as nails here in North East Hampshire.
I'm going to see if I can get a water quality report to post up but my question is, I have 23l of Wilkos Canadian Beer fermenting. Is it too late to add the Purebrew.
The Ale and IPA were all OK as they had strong flavours that I guessed masked this.
Any ideas thanks.

 

[JockyBrewer]

Do not add any form of campden/metabisulphite while yeast is active. Yeast activity will turn the metabisulphite into hydrogen sulphide and then you will have Canadian rotten egg beer.

Yeast nutrient is also needed before fermentation starts, not during fermentation. It's also not needed when using dry yeast as the yeast is dried and packaged with everything it needs.

With regards to your homebrew twang I can't say what that is for certain, but I would look at common off flavours and try to figure it out, or (ideally) take it to a homebrew club to get someone to help identify it.

My guess would be it's oxidation - it's a common beginner issue, and stronger beers are less easily affected by it. To reduce the issue, basically once you've pitched your yeast put a lid on your fermenter (with an airlock) and then don't open it until you're ready to bottle. When you bottle, fill up to about 1cm of the top of the bottle (don't fill to the brim).

 

[Jiffy176]

That was what I thought but wanted to check.
Funny things is, I've just cracked one open, colder than yesterday as I've turned the fridge down and it's gorgeous. Odd??

 

[White Rose Al]

Purebrew is slightly different to Campden in that it also contains yeast nutrients.

I use Campden in my water treatment, added to mash/sparge water 30 mins or so before all AG brewing

Purebrew added in extract kits at yeast pitch.

You will find all sorts of threads about twang on the forum. JockyBrewer makes a great point about oxidation.

Also try stick to the 2/2/2 rule with extract kits, don't get over eager and rack your beer too early. Patience is key

 

[JockyBrewer]

That was what I thought but wanted to check.
Funny things is, I've just cracked one open, colder than yesterday as I've turned the fridge down and it's gorgeous. Odd??

Colder temperatures tend to mask undesirable flavours and aromas.