The Eternal Question – Glass or Plastic

For decades, the debate amongst homebrewers about the best option for a fermentation container has been raging. Some folks adhere to the glass carboy, some folks to the plastic carboy, and some to the good old white bucket. All of them have some advantages and disadvantages, and may be worthwhile to different segments of the homebrewing crowd. Today, we’ll look at the pros and cons of the three different vessels. In the end, it’s up to you which one you choose.

Glass Carboy

These are heavy-duty vessels, essentially a glass barrel with a skinny neck that can be stopped up with an airlock.

The key advantage to a glass carboy is that the glass is impermeable to oxygen and extremely difficult to scratch on the inside. This makes infections and contaminations very unlikely. This consistency makes the glass carboy a favorite for the serious brewer, especially those who want to create beers for entry into contests, where even the slightest contamination can be an issue.

Plenty of other features make glass carboys favorites for consistency. Glass is much easier to sanitize than plastic, due to the harder surface. Also, glass is an inert substance, so there are no worries about chemicals or substances being extruded from the glass into your beer.

Glass carboys are also clear, and will stay clear over time. Plastic carboys can become milky, or scratched up to the point that the plastic is not clear. Glass allows the brewer to see the progress of their fermentation easily.

The disadvantages to glass are numerous, as well. They are much heavier than their plastic counterparts, so shipping will be more, and they will be more difficult to move. The glass can get quite slippery, making them more of a drop hazard – which is aggravated by the fact that these are breakable. They are nice and thick, so they can withstand a little abuse, but they will still crack and break.

Plastic Carboy

Sometimes also referred to as “Better Bottles,” they usually mimic the look and function of the glass carboy, but with some of the advantages of the use of light plastics.

The pros to this are many. Top of the list is the light weight – a glass carboy weighs in around 6 kilos, while a plastic carboy weighs in around 1 kilo. It might not seem like much when they’re both empty, but when they’ve got 23 kilos of fermenting beer in them, you’ll notice the difference.

The light weight makes the plastic carboy easier to clean, as well. Unlike a glass carboy, it is easy to pick up and shake to make sure that disinfectant covers all areas of the carboy.

Along with these reasons, the durability is also key. A dropped plastic carboy will rarely break, unlike a glass carboy. They can break, so dropping them out of curiosity is not recommended. They’re also cheaper to purchase, ship, and replace, making them great for the unsure home brewer.

Plastic carboys do have some negatives, however, particularly when used over long periods of time. Cleaning can cause scratches and grooves in the plastic, where bacteria can become trapped. Also, while they are easy to move, care must be taken – the carboy could flex during the move, drawing in water from the airlock. This water can contain bacteria that has settled from the environment, infecting the beer.

Plastic Bucket

The mainstays of starter kits, the basic white bucket is incredibly cheap and durable, but comes with a number of disadvantages. Unlike the plastic carboy, you don’t have to worry about the bottom flexing while moving – but you also don’t get to see your beer in action. Not getting to see the beer in action is made up for in the fact that the solid color of the bucket prevents light from getting in and effecting the beer, unlike its clear counterparts.

The large opening at the top of the bucket is a double edged sword. It makes it really easy to move liquids in, to stir, and to clean. Of course, it also creates a larger surface area that is open to contaminants over time. A plastic bucket is far more likely to fall victim to infection from airborne contaminants. Also, more area to secure around the lid leaves more possibility of an oxygen leak, which can cause vinegary odors and tastes.

The other issue comes from cleaning, as just as with the plastic carboy, the plastic bucket is susceptible to scratching. This scratching can lead to the harboring of bacterias or other substances that can cause off-tastes and odd odors.

Conclusion

You’ll also want to consider the situation you, as a brewer, find yourself in. If you are just starting out, and are unsure if this is a hobby that will be part of you long-term plans, you’ll clearly want to choose differently from someone who is planning on brewing heavily, and brewing for competitions.

The good news is that, thanks to the inexpensiveness of the plastic bucket and plastic carboy, it’s not a big deal if you purchase one of those to start, and decide to upgrade to a glass carboy when you get more serious. If you find out you just want to brew for a light hobby every so often, you might just find a plastic bucket or carboy is all you need to enjoy the process.