Barrel aging less than full barrel capacity

I recently purchased a 30 gallon whiskey barrel from a local brewery that was used once for whiskey and once for aging this brewery's porter. I believe that this barrel has been sitting dry for about 2-3 months. I've read a number of posts about how to clean the barrel & make sure that the seal is okay or restored, but what I'm most curious about is aging less than 30 gallons of beer in this barrel.

If the barrel is properly cleaned & sealed before use, is it possible to age maybe only 15 gallons of beer in the 30 gallon barrel, or will there be problems with this approach? I have a very small homebrew setup, and since I'm not doing all-grain brewing, can't convince myself to brew 6x 5-gallon batches of beer to put in this barrel & keep it in the corner of my apartment for months as a test.

Thanks!
Matt

I've personally never used a barrel so perhaps I'm completely mistaken, but I don't see how that'd be a problem. Moisture should spread, right? I couldn't imagine you'd have the top dry out and leak or anything.

You'd have the general too-much-headspace worries but no big deal.

I've also never barrel aged, but my understanding is that it really has to be completely filled. I think it has to do with uneven expansion of the staves which allows excessive oxygen to enter the barrel. I'm sure someone who knows what they are talking about will chime in, though.

Hmm.. uneven expansion could make sense. I've tried to search around online for any info on that, but haven't been able to find anything. Hopefully somebody else has tried something like this before and can lend their experience.

get other brewers and brew up 35 gallons and fill it up or you will sour the beer.