Jeff Flowers on June 4, 2014 11 Comments Pre-packaged homebrewing kits are created to include everything you need to get started on your path to brewing your own beer. However, some are also compiled for the purpose of affordability. In order to keep price down, the first component that these types of kits elect to omit is the carboy, instead substituting a fermenting bucket in its place. While the fermenting bucket can get the job done, there are certain advantages to using a carboy instead. Photo Credit: Riz94107 / Flickr Carboys vs. Fermentation Buckets Perhaps the biggest advantage there is to using a carboy instead of a bucket for fermentation is that it is transparent. Having a fermentation vessel that you can see into enables you to more easily monitor the fermentation process. Being able to see when fermentation begins and ends helps take out the guesswork and also helps you better understand what it is that you should be looking for and the specific phases that should be taking place during any given fermentation. With a bucket, you have to remove the lid, which not only increases the chances of introducing outside contaminants but can also disturb the trub or krauesen, resulting in a lower level of clarity in your beer. Carboys tend to be a bit smaller volume-wise than fermenting buckets and reduce the amount of unnecessary headspace that can create an opportunity for oxidation of your beer to occur during the conditioning phase when active fermentation may not be forcing the air within the fermenter outwards. Additionally, the tapered neck of the carboy reduces unused space and creates a channel through which oxygen can be funneled upwards and out through an airlock or blowoff tube. One advantage that buckets have over carboys is that they are easier to carry and handle because they often have a built-in handle. However, you can just as easily move your carboy around by using a carboy handle. This simple device securely attaches to the neck of the carboy just below the lip allowing you to more confidently lift it by use of a rubber grip handle. Glass Carboys vs. Plastic Carboys Carboys can come in a variety of sizes from 3 gallons all the way up to 6.5 gallons, though there are only two main types of carboys: glass and plastic. Both types will work for homebrewing use but there are advantages to each. Glass Carboys: Pros & Cons Glass carboys are the original form and are still widely used today for good reason. They are the standard because they can be used countless times without showing any signs of degradation or wear. The smooth glass surfaces inside and out are non-porous preventing anything from sticking to the carboy itself, including odors. This makes them great for brewing as you don’t want any byproducts, flavors, aromas, etc. transferring from one batch to another. It also makes them very easy to clean, especially with the use of a jet bottle washer and carboy brush. The downside of the thick glass construction is weight. Glass carboys are far heavier than plastic carboys making them a bit more cumbersome to handle. Pair that weight with the smooth construction and handling the carboy can prove to be even more challenging when either the carboy or your hands are wet. Plastic Carboys: Pros & Cons Plastic carboys are the alternative whose main advantage is the considerably lower weight. An empty glass carboy can weigh in at around 20 lbs. whereas an empty plastic carboy of the same capacity will weigh in around just 5 lbs. In addition to being lightweight, you can expect to get a little bit more grip with a plastic carboy due to its polyethylene construction, making it even easier to handle. Furthermore, the polyethylene is impermeable to air so you don’t have to worry about any kind of contamination or excessive evaporation loss. Another aspect seen to be a big advantage of plastic carboys is their potential for dual-purpose usage. Unlike glass carboys, they can be ported allowing for insertion of a spigot. This makes them particularly useful when it comes to bottling. After secondary fermentation is complete you can simply bottle directly from a plastic carboy with a spigot, eliminating the need to transfer to a bottling bucket or use a siphon at all. Plastic carboys can also prove to be easier to use when it comes to dry hopping. They typically have a wider opening making it easier to both add and extract hops. However, this wider mouth requires a larger stopper and may make it harder to rig a proper blowoff assembly for those that go that route. The major downside of plastic carboys is that the polyethylene is much softer than glass making it susceptible to scratching. While some may view scratches as being no more than a cosmetic flaw, scratches can actually present tiny crevices that can harbor bacteria. This means that you do not want to abrade a plastic carboy with any metal brewing equipment or even use a carboy brush whose stiff bristles can scratch the surface. This inability to use some cleaning tools makes them a bit more difficult to clean and also means that you’ll want to clean a plastic carboy immediately after use so as not to allow dirt and grime to really set in. Also, unlike glass, the plastic is porous, which is another reason why immediate cleaning is highly advised. Plastic carboys also technically have a limited lifespan because the plastic is softer and can wear down over time so it is recommended that they be replaced every 20-30 uses. Though, this is not a rule and merely serves as a recommendation. It should also be noted that plastic carboys are much more affordable than their glass counterparts so replacement shouldn’t cost you an arm and a leg when that time does come. Regardless of which type you choose to use, carboys can offer many advantages over fermenting buckets when it comes to fermenting, conditioning and clarifying homebrew.
Peter says July 12, 2014 at 4:12 pm I must respectfully disagree with you on 3 parts of this article. First, you mention that being able to see the active fermentation through a carboy is a plus, and while I don’t disagree with you, a carboys transparency is also a major detriment. Since there are no brown carboys that I know of, the carboy does not block any light from getting into the beer, and if left unchecked can cause skunky off flavors in the beer, a problem the bucket does not have. Secondly, you mention that carboys tend to have smaller volumes than fermenting buckets which can help to mitigate oxygenation. While again this isn’t wrong, an unopened carboy will protect against oxygenation just as well as a carboy due to the thick layer of CO2 gas resting on top of the beer from the fermentation process. Thirdly you mention that glass carboys are easy to clean, and while glass in general yes is easy to clean, if we compare cleaning a glass carboy to a plastic bucket (as this article is comparing carboys to buckets) with a much larger opening, I don’t think anyone would disagree that the bucket is far easier to clean, not requiring a special attachment for the faucet as the carboy does. Reply
jsixis says October 14, 2020 at 2:05 pm cleaning a glass carboy is just as easy as cleaning a plastic one. I clean them the same way, full scoop of oxyclean and hot water, next morning rinse and both are spotless and ready to receive a dose of star san. Glass is always easier to clean then plastic since you can see through it, you can spot dirt easier. Reply
Bob says July 12, 2014 at 4:27 pm I’ve been in the habit of buying 5 gal drinking water bottles. Use the bottle for my water, then the bottle for my carboy, then turn in for a new one for next batch. does that not address most of these issues? Reply
Jesse says July 12, 2014 at 11:21 pm Yes, seeing your beer fermenting is nice, but other than that, I see no advantage of carboys over buckets. I’ve brewed for years with buckets, and the ease of cleaning is a big reason why. Also, while I’ve used glass carboys, I’ve also broken them and nearly killed myself, so I’d be careful recommending them. I’m sure you’ve heard the horror stories, but in case you haven’t: http://www.homebrewtalk.com/f11/broken-glass-carboy-horror-stories-compendium-376523/ Reply
Bryan P says October 21, 2014 at 6:58 am I also disagree. But first I should warn everyone: If you use the carboy handles, DO NOT use them on full carboys! The glass neck can’t handle the weight. Not just that, but in general, glass can break and turn into a deadly weapon. I know one person who almost died when a carboy he was carrying broke. The biggest reason to choose buckets over carboys (glass or plastic) is that they’re much easier to clean! And cleaning is the #1 concern in homebrewing. I started with carboys and cleaned and sanitized with with zeal. But I could still see that it was dirty inside. There’s no transfer of flavor with plastic. And there’s no significant oxygen worries. I’ve kept beers in plastic buckets for up to a year without any issues. Visual clues are no guarantee that fermentation is complete. In addition to those two options, I also own and use a stainless steel conical fermentor. So, having tried many of the options, I would highly suggest that people get plastic buckets with a spigot at the bottom for easy racking. Replace them every 2 years or so. Recycle the old ones to store grain, equipment, or dozens of other household uses. Reply
Karl Tan says May 4, 2020 at 9:33 am I learnt from a local milk seller who washes his metal container (about 5-10 gallons volume) at the end of the day using fine sand, and bit of water, then shaking the mixture vigourously for a few minutes. Can this method be use to wash a carboy after emptying it? Reply
SunyJim says June 3, 2015 at 10:38 pm I also disagree. Glass carboys, aka 1930s watercooler bottles, were discontinued by the water delivery business’ because they were heavy, slippery and dangerous. The carboy handle you show should be discontinued. You’d be far better putting the carboy in a milk crate or a web-sling carry strap than that poorly designed contraption that puts all the stress on the neck of the bottle. Thermal stress. The great downfall of carboys, warm to hot liquid in cold glass makes for knife like shards of dangerous glass as the carboy explodes. Just search the internet before you buy a carboy to see the Frankenstein stitches required when your carboy shatters from bumping the ground too hard when full. Better bottles are the worst of all worlds, Stupid small opening that is hard to clean, and clear plastic to skunk your beer. You’d be far better off with a purpose built large opening plastic fermenter like every other country in the world uses to homebrew beer except good ol USA. Look up Speidel fermenter to see what a well designed homebrewing fermenter really looks like. Reply
Steve d says June 4, 2015 at 6:07 am Pass on the carboy handle. Get a brew hauler. With the handle, you’ll be tempted to move a full carboy with it. DONT! It will snap the top off and you’ll likely end up in the er to get stitches. Reply
Cory says June 4, 2015 at 3:42 pm Three words… BIG. MOUTH. BUBBLER. best of both worlds, I use the plastic ones, affordable, easy to clean, and all the other benefits of the carboy. Reply
David says October 3, 2018 at 7:09 pm I have learned so much more from the comments of this article than all the sellers of carboys. Thank you for your helpful honest reply. I think I’ll stay with my food grade buckets. David Reply
ray says April 18, 2019 at 9:33 pm The point about the plastic being able to harbor bacteria in tiny scratches is important. They can form biofilms which aren’t removed easily… You don’t want any bacteria fermenting in there or your beer will taste gross! Reply
