Have a look at 6 Best Carboys for Beer Brewing [2021]

Fermentation is a vital process in home brewing. It dictates the overall quality of the brew, and whether or not what you will finally have in your keg will be exactly what you had wanted. In homebrewing, carboys are some of the tools you will find in the homebrewer’s kit.

They are large vessels made of plastic or glass, with long narrow necks and small mouths to keep foreign particles away from getting into the beer. For a long time, they have been used for the secondary fermentation, but their use for primary fermentation is increasing, owing to the subtle benefits they come with for this vital brewing process.

Why use Carboys?

In the absence of carboys, fermentation buckets would be used. The first benefit that carboys have fermentation buckets is that it allows users to see exactly how the fermentation process is progressing. This makes it possible for brewers to keenly monitor to monitor the fermentation process and to take out any guesswork that may lead to undesirable brewing results. 

Additionally, the design of the carboys ensures that outside contaminants are kept away from the brew, and this further increases the chances of ending up with a quality brew. Also worth noting is the fact that carboys are relatively smaller compared to the fermentation buckets and this allows no headspace in the container to allow for oxidation which is normally a huge concern during the fermentation phase of the beer making process.

Types of Carboys

Carboys are available in a variety of sizes, ranging from 3 gallons all the way up to 6.5 gallons. However, there are only two major types of carboys-: plastic carboys and glass carboys. 

Glass Carboys

Glass carboys happen to be the original form of carboys, and they are widely accepted for a number of good reasons. They are considered as the standard in the industry because of their ability to be used numerous times without showing any signs of degradation or wear. 

Advantages of glass Carboys -

Impermeable to air-glass carboys have a smooth surface both on the inside and out that is completely impermeable to air. This is an admirable feature because you are able to prevent anything from sticking to the surface, and this includes odors. This makes them ideal for brewing since you can ferment or larger for a long time without worrying about foreign particles accessing your brew.

They are transparent – when brewing, it is important to observe the fermentation process so that you can understand what is happening at every stage. This is very possible when using glass carboys because they are transparent and you can see clearly through them. With a glass carboy, it will be easy for you to see the yeast cake, krausen as well as the dry hops inside.

Easier to sanitize – sanitization is a vital process in home brewing, and glass carboys are very easy to sanitize. When cleaning them, they will not form scratches which can then turn into breeding grounds for bacteria. As such, they will last longer, and you won’t need to replace them as is always the case with their plastic counterparts.

Reduced room for oxygenation – finally, glass carboys have a tapered neck which leaves little to no room for oxidation due to the reduced surface area.


In as much as glass carboys come with some enviable benefits, they also have their downsides, with the main one being their construction weight. They are heavier than plastic cowboys, and this makes handling them a challenge. When the weight is added to the smooth construction, extra care is needed when handling these vessels since any mistake may mean the end of the vessel. 

Plastic Carboys

Plastic carboys are the other type of carboy home brewers may consider if they are not in a position to have their glass counterparts. They come with the following advantages-:

Upfront cost – plastic carboys are relatively cheaper considered to glass carboys. They are by far the best way to ferment and house your young beer and highly recommended if you are just starting out as a home brewer on budget.

Weight advantage – they are incredibly light and easy to handle. At just 5lbs, it will be easier to move around a 5-gallon carboy, and you won’t have to worry about losing everything in the event of a slip because you will always be assured of proper handling.

Dual purpose – the design of plastic carboys allows them to be ported to allow the insertion of a spigot. This feature comes handy when it comes to bottling. Once the secondary fermentation is over, it becomes easy to bottle with a spigot directly; hence, no need to invest in a transferring bucket.

Makes hopping easy – they usually have a wider opening that makes it easy to add and extract hops. This is never possible with glass carboys.

The major downside of plastic carboys is the fact they are made of polythene, and as such, they are highly susceptible to scratching. Scratches may create breeding grounds for bacteria, and this is never good for the brewing process and the overall sanitation.

Secondly, plastic carboys are not completely permeable. This means that it can be infiltrated by air, and this may lead to oxidation process which may degrade the quality of the brew. Finally, plastic is known to degrade over time. Hence, they are not ideal if you are looking for ferment or larger for a long time.

Click Here to Leave a Comment Below

Leave a Reply: