Need to reduce headspace in secondary?

[Jamison]

I have a Strong Dark Belgian in primary. I will be doing secondary in a 5 gallon glass carboy. I lost a little volume through my blow-off tube, and was wondering if anyone had any tips on reducing the headspace in secondary? It is going to be there for a 4-5 weeks.
I have heard of people topping off with a similar style commercial beer. I would rather avoid that if possible. Is there something I could drop in to displace some air? It would have to be something food-safe (and sanitized of course).

 

[frazier]

How much headspace do you anticipate?

Glass comes to mind as being stable and easily sanitized. Marbles, glass beads from florist shop, etc.

 

[Jamison]

I am guessing I could be a couple quarts low. This pic is a few days old, but I still have a lot of krausen. I saw somewhere that the 5 gal. mark on a 6 gal. Better Bottle is the mid point of the top ring. I am just under that.
Good idea on the marbles. Maybe a bag of smooth aquarium rocks would be cheap?

 

[TXBeowulf]

Marbles.

Sanitize them first by either boiling or a 5 minute soak in star-san solution.

 

[Catt22]

I purge the headspace with CO2. Obviously, this would only be an option if you have a tank of CO2 available. I do this routinely when racking to a secondary.

 

[Jester369]

I wouldn't be too concerned - when you rack to secondary the beer is going to offgas a bit of CO2 and should blanket the top of the beer sufficiently. You don't need to have the entire headspace filled with CO2, just enough to keep the air away.

 

[tunoffun]

I purge the headspace with CO2. Obviously, this would only be an option if you have a tank of CO2 available. I do this routinely when racking to a secondary.

That's what I was going to suggest, though the marbles sound like a great idea as well.

You could still purge w/ co2 without a tank. If you have something fermenting in the primary, just route the blowoff hose from it into your secondary allowing a little room around the sides so you don't pressurize it (maybe just loosely lay a star-san soaked paper towel around the edges for a couple hours until you feel the headspace is filled. Or - you could do the same making a small batch of quick-wort from DME for the sheer purpose of generating co2.

The more I write, the more the marbles make sense

 

[tunoffun]

I wouldn't be too concerned - when you rack to secondary the beer is going to offgas a bit of CO2 and should blanket the top of the beer sufficiently. You don't need to have the entire headspace filled with CO2, just enough to keep the air away.

What if he drops the temp?