Stepping up to carboys
By Gregg Smith
Dateline: Vancouver, Washington, location of the now defunct Lucky Brewery. Makes you
wonder just how lucky it was. The owner is moving the fermentation tanks to a new
brewery and a crew is treating the giants with more care than you'd expect steel tanks
would warrant. As the process goes on crane operators and riggers watch anxiously while
the vessels are slowly lowered to the security of a transport cradle for their trip to a new
home in China.
Why all the care in handling? Simple, those tanks were built in the days before stainless
steel. Beer in regular carbon steel tanks will pick up ions from the metal which even
stainless steel can transfer into the finished brew. Those older fermenters didn't have that
problem because the beer was protected in the tanks by a lining of glass. In fact many large
breweries still use this method.
What's the point? Glass is one of the most inert containers devised and as a storage
medium it will have minimal impact on the finished beer.
The implication for the home brewer is cleaner beer, and the application is the glass carboy.
Most homebrewers start off with a kit which contains a food grade plastic fermenter. It will
serve as a reliable primary vessel for several brews but note: it does have a limited life. The
reason big commercial brewers don't line their tanks with less expensive plastic also
applies to you. Over several cleanings the plastic acquires small scratches. Although nearly
invisible to the naked eye these will act as the breeding ground for all types of beer
infections. Even microscopic sized scratches are potential beer ruining trouble spots.
Glass surfaces are smoother and more durable and should lead you to switch eventually to
glass carboys as both your primary and secondary. When you decide to take the plunge
there are several considerations, and the first of these is size. A six and one half gallon
capacity carboy will function fine as a fermenter and in a five gallon batch the additional
head space will reduce the potential of blowing a foamy mass through your airlock.
However, a five gallon also has its advantages. Some brewers believe the foamy head
which forms on the top of fermenting beer contains overly bitter resins which should be
"blown off". Of course to do this you need to rig a blow off tube which we'll get to shortly.
The next consideration for either size carboy is the cap or plug. Again each has its
advantages. The cap (those weird looking orange things) can hook up either an airlock or a
blow-off tube by means of two fittings molded into the top. The problem with the caps is
that after several uses they will leak where they grip the carboy. The alternative is a plug but
for these you'll need two: one to fit the airlock and another sized for a blow-off tube. Of
course if you'd prefer the cap there is a simple way to avoid leaks. Just use a rubber band
wrapped around the outside of the cap where it grips the carboy mouth. Doubling over a
stout rubber band a couple of times will usually do.
Here's another useful hint. If you go the route of a smaller carboy and use a blow off tube,
how do you keep the hose from crimping? A blow off tube uses tubing connected to the
carboy cap with the other end dropped into a bucket one third full of B-Brite. Under normal
conditions the hose will bend under its own weight at the top point of the loop from the cap
down to the container of water (a blow off works like a giant airlock). To avoid the
crimped area, which can clog and cause the hose to pop off, resort once again to the
brewers trusty friend - a rubber band. Place a large one around the neck of the carboy and
then run the hose up in a loop and back down through the rubber band. Adjusting the
amount of hose forming the loop will eliminate the crimp and hold the hose in place. (It'll
look like a the hook of a candy cane with a rubber band across the top. Do remember if
you use a blow off tube that they become dirty hoses which can be difficult to sanitize, so
you'll need to replace them often. There are your options; you decide which system is best
Another carboy gadget which proves quite useful is the carboy handle. A caution here - be
sure to tighten them firmly around the carboy neck. These are worth the investment
because five gallons of beer will weigh more than 40 pounds. Don't be afraid to use a
screwdriver and pliers to tighten the handle a bit more than hand tight. And occasionally
remove the handle and clean both the carboy neck and handle.
One final hint. When you drain your carboy after sanitizing you'll wonder why it empties
so slowly while shaking and noisily going CHA-LUG, CHA-LUG, CHA-LUG... well
there's a way to avoid that too. You can either buy a vacuum breaker - which is nothing
more than a short piece of plastic, or make your own by utilizing your curved, hard plastic
racking tube. Simply rest the carboy's shoulder on the edge of the sink and insert your
racking tube into the carboys neck. Surprise! the noise will go away. Without getting too
technical what you did was to give the air one path to get in (the tube) and the water another
path to get out without them running into each other and battling for limited space in the
So there's your primer on carboys. But what do you do with the old plastic pail? Don't
throw it out, just designate it as your sanitation catch all. Fill it with sanitizer when you're
ready to brew and dump in all your various brew gadgets: airlocks, carboy caps, hoses,
funnels, etc. Often you can even see the commercial brewers using white plastic pails for
just that purpose. That's all for now and Good Brewing!
© Gregg Smith