Glass Carboy Or Plastic Bucket For Fermentation: Which One Should You Use?​

One of the things that I like about homebrewing, is hearing the opinions from other fellow brewers on why you should or shouldn’t use a particular item or why you should or shouldn’t do something a certain way.

When it comes to the brewing of beer, there are a couple of main talking points that continue to be a huge topic of discussion.  One is whether “secondary fermentation” is a good idea or a bad idea. And the other is if you should use a plastic bucket or a carboy for fermentation.

Both plastic and glass do have certain advantages and disadvantages, but both definitely have a place in every home brewery.

Glass Carboy Or Plastic Bucket: Types Of Fermentation Equipment

In this article we will discuss a few of the pros and cons of using different fermenting vessels, and whether a glass carboy vs plastic carboy vs plastic fermenter bucket is the right choice for your brewing needs.

When it comes down to the fermentation equipment, you really do have many options to choose from, ranging from glass or plastic carboys, plastic buckets, or even a conical fermenters. But for this article, we will focus on differences between using glass vs plastic for fermentation.

Glass Carboy

Many homebrewers prefer to use a glass carboy for fermentation and has some noticeable advantages other than looking cool.

Two of the main reasons that a glass carboy is preferred by many brewers is because it is impermeable to oxygen, which is a bad thing during fermentation.

The another advantage is you can actually see and monitor what is happening during the fermentation process without guessing, and avoid taking the lid off of the plastic bucket which can increase the risk of a serious infection.

5 gallon glass carboy

However, while is is great to be able to see what is going on inside of the carboy, one downside is that you must protect the beer from light.  Protecting the beer from harmful UV light is necessary to avoid off-flavors and a skunky beer.  Try to keep the carboy in a dark area of the house or keep it covered with a blanket to avoid exposure to the light.

While a glass carboy can be used for primary fermentation, it is also recommended to be used as a second fermentation period if the recipe or style of beer calls for it.

If you are using a beer ingredient kit, most of the directions are designed to use a plastic bucket for the main fermentation, and then an extra “optional” step is often recommended, which is to transfer the beer to a carboy for “secondary fermentation” until you are ready to bottle or keg your beer.

This is where the continuous debate about the need for secondary fermentation comes into play.

Also, since there are so many different sizes of carboys, with some being smaller in volume size, there always isn’t as much headspace available like there would be in a plastic bucket.

If you are planning to use a carboy for primary fermentation, you might need to use a bung and “blow-off” hose instead of a standard airlock. During some vigorous and violent fermentation periods, the krausen and foam can literally blow the stopper and airlock right from the mouth of the carboy and create a big mess.


  • Doesn’t scratch like plastic
  • Easy to sanitize
  • Can see fermentation taking place
  • Not-impermeable to oxygen


  • Can break and cause serious injury
  • More expensive than plastic
  • Much heavier than plastic and can be awkward to move

Plastic Fermentation Bucket

If you bought a complete beer making kit, or compiling your own beer equipment kit piece by piece, you most likely will have two different plastic fermentation buckets. One bucket is used for primary fermentation, and the second bucket will be used as a “bottling” bucket.

To keep the cost down, the basic and inexpensive beer equipment kits include a food-grade plastic fermenting bucket which is completely fine and will do the job.

While there are definitely some strong points for using a plastic bucket for fermentation, there are also some drawbacks that come along with it too.

plastic ale pail for fermentaion

First off, plastic buckets are very cost-effective compared to other styles and can be used primary, secondary, and bottling.  Besides the prices, one of the best reasons to use plastic is because they just don’t break like some other materials.  In addition, having a large opening makes it easy to stir and add fruit or other spices.

However, even though the plastic won’t break, it can be scratched rather easily which then can harbor bacteria that can lead to an unwanted infection.  Also sometimes you might need to check on the fermentation process by getting a sample for a hydrometer reading.  Anytime you open a lid, you take the chance of your beer becoming oxygenated.


  • Inexpensive
  • Easy to transfer wort
  • Lightweight – Easy to carry and store
  • Will not break or shatter like glass


  • Can scratch and give bacteria a place to hide
  • Cannot see what is happening inside
  • Oxygen can enter through the plastic and ruin the beer

Final Say

Nobody can say that one or the other is better. No matter what you decide, both glass and plastic can and will work just fine for any homebrewer. It all comes down to personal preference and what you are comfortable with.

Not all brewers are the same, just like not all equipment is the same.  Beer brewing is about experimenting with new recipes, techniques, and equipment. The only way to know what is better for you, is to test and see what works best for you.

Happy Brewing!

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