You would think that the choice is simple when choosing a carboy. You have glass carboys and you have plastic carboys. But is it really that simple? An ongoing debate has been in the brewing world about plastic or glass carboys ever since carboys have been around on which one is the best option for you when fermenting.
To make life a little bit easier we have created the only guide you need when it comes to knowing about plastic vs glass carboys. Before we dive in, it’s important to get a general understanding between the two.
Glass Carboy’s
A glass five gallon carboy weighs 13 pounds and take a #6.5 stopper or if you like a tighter fit #7 stopper.
Reasons why people like glass carboys:
- They last a very long time
- They usually don’t scratch when you clean them with a carboy brush
- Oxygen cannot penetrate it so you beer or wine will not spoil
- Flavors don’t stick in glass
- They Come in a variety of sizes 5 gallon, 6 gallon, and 6.5 gallon
- They are heavy (13 lbs empty and 5 gallons of water weighs about 42 lbs so your looking at approx 55 lbs when said and done)
- Storage might be an issue
- If they happen to get dropped they can shatter or break
- They can be expensive to ship
- They are light
- Storage is usually not an issue
- Less expensive than glass
- They tend to get scratched with cleaning
- Storing beer in plastic may result in off flavors
- They don’t come in 6.5 gallon so you may need a blow off in some cases
- Cannot take negative pressure
- When lifting and moving the carboy it can and will suck water from air lock into fermenter
As you can see, the stopper is much smaller then the lid.
The 6 Things You Need To Know About Choosing Glass Or Plastic Carboys
1) One’s Heavy One’s Not
The first thing that you’ll notice when looking at plastic and glass carboys is that plastic carboys are significantly lighter, and for the most part are shatter proof. Being light and virtually unbreakable really makes storage fairly easy. Glass on the other hand is heavy and can break.
2) Plastic Carboys Are Made To Avoid Sediment With Racking
One advantage of plastic carboy’s that I don’t hear many people talk about is the fact that there is a divot at the bottom of the carboy. This is raised up significantly higher then the glass carboys. This is a benefit because the yeast/sediment will fall further down in a plastic carboy then in a glass carboy making racking a breeze with out sediment. To me this is one of the biggest advantages of a plastic carboy over a glass carboy.
A picture of this can be seen below comparing the two.
3)Plastic Carboys Have Ways To Help Clarify
Another advantage that I see with plastic carboys are that the sides come out significantly more then glass carboy’s. Plastic carboys also have rivets all over the dents that come out as well. The reason that plastic carboys have these dents filled in with small rivets is that, “floaties” such as yeast or other sediment will hit these dents/rivets and will fall down. With the glass carboys they have this feature but again on a more down sized fashion.
Pictures can be seen below comparing the two.
4) They Both Break
So how often do glass carboys break? I’m not really sure to tell you the truth. I can tell you that I’ve heard some customer horror stories with them falling on there feet, bruising the foot and then slicing it open with the shards of glass. I can also say that breaking glass carboys has happened to me as well . But don’t think for a second that that Better Bottles are invincible. They do scratch when you use a carboy brush. The other problem with Better Bottles is that if you pour in hot liquid (over 120 degrees) you will most likely melt the plastic aka breaking it too.
Personal Experience With Breaking Glass Carboy:
The worst was when I had 6 gallons of red wine explode all over my basement when using a glass carboy. The odd thing about it was that I set it down on a folded towel, and I set it down very lightly. All of a sudden it started to crack and then BOOM! It exploded. It led to a long night of moping, cleaning, and air freshener. For a full month walking down into my basement and smelling the red wine lingering in the air served as a constant reminder of a mistake I promised myself that I would never repeat.
5) Better Bottles Can Suck… Literally
A nice aspect to glass carboys are that when you end up picking them up, while it may be heavy, you don’t have to worry about the water in the air lock getting sucked into the carboy. With plastic better bottles if you pick it up by the neck, the better bottle will bend/flex (because it is plastic) making a suction and by the time you realize what is happening you will see dirty water just get sucked into your brew. Not the best way to start your bottling or racking.
An easy solution to avoid getting dirty water sucked into your brew when using a better bottle is, just take the stopper and air lock off before you plan on moving your beer. When glass carboy users are using all ammo to try to convince others to use glass I seem to see them resort to this problem with better bottles too. I’ve never really understood why this is a big deal because all the times I’m moved my fermenter I am doing it not for a work out, but because I’m going to be siphoning it and the top is going to have to come off regardless. So to me, not a big deal, but hey – everyones got there thing.
6) Glass Can Not Only Break, But It Can Break The Bank
The cost difference between plastic and glass at appearance may not be to much if you are walking into your local home brew shop and you don’t have to pay for shipping. But if your plan on buying it over the internet be prepared for a pricey shipping on the glass carboy. It weighs 13 pounds and has to get shipped with care/special packaging. When comparing glass to plastic, plastic is by far the easier one of the two to ship.
Conclusion
Like I said in the beginning of this post, I’m really not trying to convice you one road or the other. If you don’t own a carboy yet and your thinking about getting one, start off with one style and then get the other one later on. You should be the judge of how you like your carboy, and only you. There really is not a, “better one” just preference from your own experiences. Everyone has an opinion, and the only real way to learn is by experimenting.
Regardless of what you use, I would love to hear from glass and plastic carboy users and your personal experiences with them. Every brewer has them.
Jay's Brewing Blog 
September 29, 2011 at 9:42 am
You couldn’t have posted this at a better time. I’m working on my second batch and was planning on getting a carboy when I come into the shop. I came in a few months and picked up a starter equipment kit and the Rogue Hazelnut Brown Nectar ingredients kit (Which came out great by the way). I’m going to do a wheat beer this time around and wanted to upgrade to a carboy for secondary fermentation. I was still going to use a bucket for primary fermentation, but only for about 7-10 days. Then I would transfer it to a carboy. I’ll probably be stopping into your store in a week or so to get everything. I have a few other questions about this next batch and wanted your opinion as well. Cheers!
September 29, 2011 at 10:59 am
I’m glad that your brew came out great as well as you found this post to be useful. Using a bucket for the primary and a carboy for the secondary is a pretty common practice. I would recommend that you do that for a wheat beer any ways unless you were to use a blow off tube for the carboy which I can talk to you more about it when you come in.
Cheers,
Derek