Glass vs. Plastic Carboys - Which Is Better?
Why You Should Care | Comparison
Logical Arguments and Explanations |
Does It Really Make A Difference?
There seems to be a lot of debate among home winemakers these days
about the type of carboy that should be used during fermentation
and aging. Are glass carboys better than plastic ones? Or is it
just the opposite? Most importantly, does it really matter?
Yes, there IS a difference - and grapestompers.com hopes
to illustrate why there is a clear choice when it comes to selecting
the type of carboy to use.
When all the evidence is weighed (see below), the choice appears
to be obvious. Despite this evidence, the selection of one type
of carboy over another may have little to do with the facts; for
many winemakers, it simply boils down to a matter of preference.
Use the chart below to see (in bulleted format) the advantages and
disadvantages of glass versus plastic carboys:
- You can see what's happening during fermentation and clearing
- Glass is easier to clean and sanitize than plastic
- Glass is impervious to scratching during normal cleaning
- Easier to get a good airlock seal
- Glass is inert; no chemicals or solvents to leach out
- Little or no oxidation occurs to wine during long term
- Glass is breakable, and thus more dangerous to handle
(slippery when wet)
- Glass is heavier than plastic
- Sunlight through clear glass can harm wine
- Plastic carboys may be cheaper to purchase than glass
- Safer to handle and lightweight. If dropped, there's no
- More difficult to monitor wine during fermentation and
- Very easy to scratch surface while cleaning; even microscopic
scratches can harbor bacteria that will ruin your wine.
- Plastic is much more apt to harbor off tastes, odors,
- Plastic carboys may tend to make wine more difficult to
- More difficult to get a good airtight seal
- Oxygen diffusion across barrier more likely during long
term storage. Can you say vinegar?
- Depending upon the source, plastic carboys may leach solvents
when filled with acidic or alcoholic fluids.
- When full carboys are lifted, the bottom may deform (pooch
out) and draw in the water from the airlock.
It's simple - Glass is easier to clean and keep clean than plastic.
And, because it's clear, it's easy to see if there is any film or
gunk on the inside of the carboy. Plastic is easier to scratch during
the cleaning process, and in these microscopic cuts or gouges, harmful
bacteria and other nasties can hide, waiting to pounce on your next
batch of wine and ruin it. Even if not scratched, plastic contains
microscopic pores that can harbor the same harmful elements.
Ask any amateur winemaker... the number one reason why wine "goes
south" is a lack of proper sanitation. Having a carboy made
of glass is your best insurance against this common problem, since
it is so easy to clean.
Glass is not porous to oxygen like plastic. In the scenario of
bulk aging wine in a plastic carboy, you'd really want to keep a
close eye on the oxygen levels.... we've all heard stories of wine
turning to vinegar because so much O2 was able to diffuse
across the plastic barrier!
Glass does not harbor "off" odors and tastes like plastic
can. Try this experiment: put something smelly (like anchovies
or sardines) in a sealed Rubbermaid or food grade plastic container,
and also put a portion in a covered glass dish. After a period of
time (week to a month, which would simulate aging in a carboy),
remove the smelly stuff and wash each container as well as possible.
Despite repeated washings, you'll still be able to smell the remnants
of the substance in and around the plastic container, but not in
the case of the glass dish or bowl. Imagine accidentally imparting
an off odor like that to your wine because you used a plastic carboy!
Even though plastic carboys are safer to handle and won't break,
we believe that the advantages of glass - most notably those that
ensure your wine won't be tainted - are more than enough to convince
This is why grapestompers.com recommends (and sells only)
glass carboys for
fermentation and bulk aging.
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