Headspace in secondary

[myndflyte]

I made a cyser and have transferred it to the secondary. I blasted the headspace with CO2 for about 45 seconds. Should I top it off with more cider or will the blanket of CO2 be enough to prevent oxidation?

 

[Maylar]

Depends on how long you intend to leave it like that. The CO2 will eventually diffuse with oxygen that permeates the airlock. A couple weeks for clearing is OK (done that with ciders), but beyond that you need to address the headspace. Topping up that much with cider will dilute your honey a lot - if you can accept that then OK. But I'd be looking for smaller vessels.

 

[mr_stout]

I saw a guy sanitize marbles and used them to fill up space in the fermenter to displace the air.