[Buddylee000]

It looks like I'm about half to a full gallon short of filling my barrel. My thought was to just open a few beers of similar style and add them to the barrel. Is there any issue with doing this?

[HopDen]

Are you talking about a bourbon/whiskey barrel? If so, don't worry about the head space. I just kegged a RIS that was in the barrel for 11 months and no ill effects on the beer. I put 25 gallons in (25 gallon barrel) and with evaporation I had 21 1/2 left. Now with being said, I would not barrel age a beer under 7% abv for anymore than 2 months and checking it often.

[kramerog]

The headspace can get moldy particularly if the barrel's last use was not bourbon or other distilled alcohol and oxidation increases the more the headspace.  So I top off initially and repeatedly.  Part of the repeated topping off relates to when you have a group of people putting beer into a barrel, you want everyone to get their fair share at the end - the last person to get beer out shouldn't get shortchanged.   I suppose there could be more than 1 right answer here.

[Kevin]

Rotate your barrel regularly to avoid the moldy headspace... and to keep those staves wet and properly swelled up.

[HopDen]

Rotate your barrel regularly to avoid the moldy headspace... and to keep those staves wet and properly swelled up.

I don't agree that you need to rotate the barrel. You don't want any sediment to keep churning back into the beer. I have barrel aged with 3 different barrels and used them all with 2 different beers for extended time frames. I haven't had any mold whatsoever or at least what i could see with the naked eye. The barrel is going to be tight and oxygen ingress is micro.

[Buddylee000]

Thanks for the feedback. I think that the best thing to do here for myself is to do nothing and let it ride. I think that I have a higher chance of oxidation if I add a couple of beers than I do with leaving the barrel with the additional head space.