Cider already started fermentation

[Fordzilla]

I'm currently out of town. Yesterday I got 8 gallons of hard cider from a friend that have already started to ferment from wild yeast. I'd prefer to ferment it with US-05. Can I just pitch the US-05 or do I have to treat it with campden first?

When I got them I immediately put them in the fridge to try and stop the fermentation. When I get home tonight and have access to my brewing equipment again I will take a gravity reading to try and get a rough idea how far along it is already.

 

[Yooper]

I don't think there is much you can do to get rid of the wild yeast. The idea of campden is to kill most of the bacteria and some of the wild yeast, and then pitching your chosen yeast strain to outcompete the wild yeast before it takes hold. Once it does get going, campden shouldn't do much to it, and pitching a new yeast strain probably won't either, as it's probably got a pretty big colony if it's been actively fermenting.

It's worth a try if you really want to do it, to chill the cider and then add the campden and try to get the S05 going.

 

[Fordzilla]

I'm just afraid I will end up with 8 gallons of funky tasting cider. Or, even worse, that it's bacterial activity I'm seeing.

 

[Yooper]

I'm just afraid I will end up with 8 gallons of funky tasting cider. Or, even worse, that it's bacterial activity I'm seeing.

Yes, that is a big risk with wild fermentations.