Question about reducing headspace

[J2W2]

Hi,

I'm getting ready to brew another batch of a Pliny the Elder clone I really like. For dry hopping, I use a plastic Big Mouth Bubbler with a Depth Charge for the hops. This has really worked well on my prior batches, but with all the hops additions, I'm lucky to get 4.5 gallons in the keg. Those results are using my 5-gallon Big Mouth Bubbler.

I also have a 6.5 gallon Big Mouth. I've thought about increasing my batch size a little and shooting for 5.5 gallons or so in the secondary. That would still leave quite a bit of headspace. I've read about using satirized glass marbles to reduce headspace. I'd need a lot of marbles, and I assume at least one advantage of using them would be that they fit in the narrow neck of a regular carboy - not an issue with the Big Mouths.

I have a case of 16-ounce PET plastic beer bottles, and I was wondering if there would be any reason why I couldn't fill several of those with santizer, put the lids on tight, sanitize the outside of the bottles and use those to offset most of the extra space in the Big Mouth.

Does anyone see any issues with that? Thanks for your help!

 

[Jag75]

I've used 7.9 gallon fermenters that have had 5 to 5.5 gallons fermenting in them. Never has there been an issue . You will be fine with a 5.5 gallon batch in your 6.5 fermenter.

 

[mannye]

In the dark ages, when corny kegs were still used for soda and were plentiful, we would use a trick to keep the rubber pickup tube on top of the beer and away from any yeast deposits that fell out of suspension. We would take a medicine bottle that was airtight and tie it to the end of the hose so it would float the hose at the top. The procedure back then was to sanitize it with that nasty smelling sanitizer we used back then, I forget the chemical name... smelled like sulfur... close it up and fill the keg.

Never had a problem.

If the bottles are water/air tight, just fill them with distilled water after making sure they are clean and sanitized. That way is anything happens and they leak, it will just be a little water and not Star San or Idophor leaking into your product.