Re: Wine Aging

Ray, I have been making wine for a lonnnng time. I bulk age in carboys
where possible and have never had a carboy burst on me while filled
with wine.  Further, I don't personally know anyone who has.  I broke
one once when I set it down too hard on a cement floor, but that is my
only casualty ever.  I don't think your worry is all that
well-founded.  Carboys are pretty darned strong, even the cheap ones
made in Mexico (I have eight of those).

As for the risk of sucking airlock solution into the wine, I think
that too is much overstated.  When bulk aging, I add 4 drops of
glycerin to the airlock and then 10% sulfite solution until the liquid
occupies about 1/3 of airlock.  With the glycerin, the liquid in the
airlock will not drop 1/4 inch in four months.  Further, with the
airlock filled to only 1/3, the liquid cannot be sucked up into the
wine;  there just isn't enough of it to do that.

Ullage of one to one-and-a-half inches is all the cushion one needs
for a  five- or six-gallon carboy.  I wouldn't exceed two-and-a-half
inches for a twelve-gallon demijohn.  If the top of the wine ever
approached the bottom of the bung, all you need do is watch it and
remove a bit with a wine thief if it made you nervous.  I currently
have ten carboys and 24 gallon-jugs under airlock.  I look at every
one of them at least once a week except when I'm out of town.  If
something is going wrong, I see it.

You make bulk aging in carboys sound like a crap shoot and it isn't. 
The only way it can go wrong (in my experience) is if someone (or the
dog) bumps the airlock and jars it loose -- or if one is negligent.

Sorry to be critical here, but I just think you are over-stating the
dangers of bulk aging in glass.

Jack Keller, The Winemaking Home Page
http://winemaking.jackkeller.net/