Plastic vs. Glass Carboy - old debate, but looking for experience

[JiP]

I know that this has been debated a million times, but I haven't found the answer I'm looking for... all posts seem to state the same things, which are kindly repeating words of wisdom but not based on personal experience.

Does anyone have direct experience with the theory of "tiny scratches" in plastic carboys harboring bacteria? In other words, has anyone had an infection problem solved by switching to glass, or has anyone done a bacteria sample from plastic carboys after cleaning and/or sanitizing?

I have a persistent "sour" aftertaste in my last few batches, and I'm trying to narrow down the problem. It could be the carboy, the wort chiller, the bottling equipment, or the bottles themselves. I found one post that said his problem was fixed by diligent cleaning of the wort chiller instead of relying on the boiling wort to sterilize it, but I haven't heard direct experience with plastic carboys vs. glass, and don't know if I should scrap my plastic carboys and buy glass (expensive and wasteful, especially if that's not the cause of the problem), so any feedback would be appreciated!

Thanks in advance!

 

[hopsalot]

JiP,

You are going about your problem the right way, ensure you practice is clean then target your equipment. What kind of chiller do you have? Periodically I will boil the entire chiller to clean it out, and always run boiling water through it at the beginning of the boil, then sanitizer before chilling.

Are you speaking of buckets or PET bottles? If you think a cheap plastic bucket is causing contamination, throw it away! Plastic buckets are soft and definitely have a short life in a homebrewer’s hand. Personally I gave up on plastic buckets, switched to PET bottles and have never had a problem with my fermentor. Glass is the safest but heavy and dangerous if dropped.

To answer your question, I have not had infection problems in the past caused by scratches in my old plastic buckets, but I have had infection problems caused by other equipment that was neglected, such as a scratched bucket. Plastic equipment is cheap and not made to last forever.

 

[LandoLincoln]

Do you keg, or are you ever planning on kegging? If so, then buy a corny keg and use that to ferment a batch in. Then later on you can use it for actual kegging. I wish I had invested money in corny kegs instead of carboys.

 

[audger]

fermenting in a 5 gallon corney sucks IMO (unless you are doing <4gallon batches). you can really only ferment 4.5 gallons AT MOST, and then you would still get a lot of blow off and lost yeast out the top (in top-fermenting varieties). if you want to brew enough to fill a whole 5 gallon corney, you really need two kegs to ferment in.

however if you had a 6 or 6.5gal carboy, you can fit a whole 5 gallons of beer and get one full corney keg out of one carboy. when you are brewing 10 or 20 or 30 gallons at a time, cleaning 3 carboys instead of cleaning 6 corney fermentors is a BIG difference. not to mention carboys dont need to be disassembled to be cleaned...

glass is really hard to beat. its completely impermiable to gas and liquid, more difficult to scratch then plastic or even steel, its clear so you can see where any dirt may be hiding, you can heat sanitize it, use caustic chemicals or acids, whatever.
the only downside is you cant fit your whole hand in them for cleaning, and they are pretty fragile.

i have a plastic 8 gallon fermenter for trasporting grain from the LHBS so i dont keep using all their plastic bags. i could use it as a fermentor if necessary, but probably wouldnt just because it scratches just from looking at it, and plastic soaks up odors like a sponge. i dont care how many times you rinse your bucket afterward; if you have washed it with bleach before, i will be able to smell it; and if it smells like bleach im not using it in my beer.

 

[modobrew]

if you use the cheap brewers ale pale please check out my post from earlier this week. Be sure to check this if you plan to use these. Would hate for the same thing to happen to a fellow brewer.

 

[JiP]

Thanks for the feedback.

Here's my conclusion, after feedback from this site, reading other sites, asking the brew shop, and a couple of batches to test the theory.

It was the bottling bucket and tubing, specifically the springs and valves.

I had tried new carboys, clean ones, etc. but the sour taste persisted. It actually varied between bottles, and a few bottles were fine.

No one has written about getting a bacteria from scratches in plastic carboys. I don't believe that bacteria could survive my cleaning, anyway. But, I disassembled the springs in bottling tubes and the valve in a bottling bucket had many spots that are shielded from sterilizing solution if not moved during the cleaning process. IMHO, this sounds like a theoretical problem that makes sense and became what people believe common knowledge.

I started kegging, but enjoy having a few bottles on hand so I'll be more diligent cleaning bottling equipment in the future. I'm keeping the plastic carboys - they're lighter, easier to handle, I'm not scared to drop them (therefore more likely to drink a beer or two during brewing), and I suspect that the concerns about oxidation are another theoretical problem that has grown into a perceived problem. I secondary ferment strong ales or dry hopping in a glass container, which is smaller than the plastic to minimize air space. But, this is only because I already had one (because of the theoretical problem of oxidation). I wouldn't worry about it in the future, as more oxygen probably gets put in during even the most careful racking than could penetrate that much plastic in 4-8 weeks. Also, for me, I simply don't like my food/drinks sitting in plastic for a long time regardless of any scientific reasoning.

 

[TravisT]

I had a infection while using a plastic bucket and could not get it sanitized. I tried a heavy over night bleach bath, over night star san, but it still kept producing vinegar/sour beers. I lost 3 batches before I wised up and bought a glass carboy.

 

[ThatGuyRyan]

I have never had an infection issue with plastic buckets or carboys and even some that have big ass scratches in them. When I do have to use one of my scratched backup bucket or carboys I do clean and sanitize it with everything I got. And when I did get an off taste in a few batches I switched from plastic to glass and from keg to bottles and when I still had the issue I tossed all my hoses and replaced them. Problem solved. I now regularly toss all my cheap hoses every few months and even pick up a new auto siphon every now and them just to be safe.

As for the bottling bucket I tossed mine once I went to keg. And even when I bottle I still use my keg. Just mix you priming solution in the keg and put it on about 5 psi and use a cobra tap or the homemade beer gun to fill your bottles. Less mess and less oxygen coming in contact with your beer and it’s easier to sanitize the keg than the bucket IMO.

 

[hopsalot]

It was the bottling bucket and tubing, specifically the springs and valves.

.

Same here, the only infection I had was from the spring and valve in a bottling wand

 

[marmonduke]

I also had a couple issues with the hoses and autosiphons. I switch out my tubing often and switched from plastic siphon to SS siphon.

 

[JiP]

For anyone reading this from an internet search, here's my experience two years later... I switched to glass carboys, but still had an infection in some of my bottles, not all, implying something in some bottles but not others or simply poor sanitation of my bottles. I mostly keg now, and haven't had an infected keg. I'm still working on improving bottling though, because I like aging beers in bottles.

I kept the glass carboys because I prefer them based on the diameter/hight ratio, i.e. it has more vertical headspace for foam during fermentation, and less wasted beer when racking off the yeast trub.

 

[passedpawn]

For anyone reading this from an internet search, here's my experience two years later... I switched to glass carboys, but still had an infection in some of my bottles, not all, implying something in some bottles but not others or simply poor sanitation of my bottles. I mostly keg now, and haven't had an infected keg. I'm still working on improving bottling though, because I like aging beers in bottles.

I kept the glass carboys because I prefer them based on the diameter/hight ratio, i.e. it has more vertical headspace for foam during fermentation, and less wasted beer when racking off the yeast trub.

Wow, thanks for the followup!