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Glass and Plastic Fermentors

The debate rages on I suppose.

I have been using a combination of glass and plastic fermentors off and for the last 11 years.  In fact, I still ferment in my original bucket fermentor that came with my first equipment kit.  Because of that I really do not subscribe to the fear factor some people have regarding scratches.  Plastic can get scratched which is why you should never “scrub” a plastic fermentor with something abrasive like steel wool, or even one of those green pads from scotch bright.

However, some would have you believe that even rubbing your hand across the surface of your bucket can create “micro” scratches that harbor bacteria.  NO.  I don’t buy that for one bit. My evidence is the fact that I’ve never had a batch go bad because of bacteria or an infected batch that I could trace to the fermentor.

To get long term use from a plastic bucket though, you do need to be cautious.  If I have some stuck on yeast, beerstone, or trub; I tend to soak the bucket overnight with PBW, from Five Star Chemicals.  Then a good strong rinse with a hose and out it all comes.  I think the biggest thing I have done to protect the inside of my buckets is that I have never nested the together.  I have three buckets and they always sit separately.  I brew in a garage, and the exterior base of my buckets are pretty roughed up from getting slide across the concrete floor.  I also don’t do a great job cleaning the exterior of my equipment.  So there is often a lot of grit and stuff stuck there as well.  If I were to nest the buckets for storage, I am sure my buckets wouldn’t have lasted as long as they have.

Well with that all said, I have been slowly moving towards using only glass during fermentation.  My buckets are getting tired and worn.  Furthermore, I am staring to use them for other things like storing tubing and racking canes.  I also occasionally use them for holding crushed grain for a big batch as I am milling.  I also use them for measuring water.  I collect wort in them from the mash tun, preboil.  So when my buckets are full of fermenting beers, my brewing process sort of comes to a halt.

And glass does offer several advantages over plastic, namely visibility and oxygen transfer.  My most recent new brew was the Berliner Weiss.  That beer uses an intentional pitch of lactic acid bacteria.  Being able to see inside the fermentor has been a plus so I can learn better what has been happening in the fermentor.  I don’t always feel the need to watch my ferment.  However, as I start to pay more and more attention to the subtle details of making beer; knowing when a certain yeast strain really starts to drop out, or come to krausen is a good benefit of the clear glass.
Glass is impermeable to oxygen.  So that is one less factor in trying to get fine control over the brewing process.  Each year Zymurgy magazine publishes the recipes from all the NHC winners.  Last year, they also deonoted in each recipe whether the beer was done in glass, steel or plastic.  Almost everyone was in glass, a few in steel and no one was in plastic (at least maybe no one wanted to admit to that?).

Regardless, of my respect for plastics I am switching over entirely to glass as things progress in my brewery.  I don’t think I’ll be replacing my plastics for more plastics.  Yes, yes call be a brewing snob, but that’s just the way I feel about now.  Ask me a couple more years from now, and I am sure I’ll be switching back to plastic complaining of narrow openings and breakablity of glass.  Or maybe by then I’ll be in stainless steel.

(Oh, and I have given up on Better Bottles.  See this post and gleen my primary reason for that.)


Fusel Alcohols


Berliner Weisse Recipe


  1. floodx

    An alternative to both glass carboys and plastic buckets – stainless steel milk cans. You can get them from http://www.lehmans.com for about $140 (a little pricey) for a 5 gallon (it is really almost 6 gallons for I put a 5-5.5 gallon batch in it and it still has about 2-3 inches of headspace for krausen) and $220 (I think) for a 10 gallon. Sometimes you will seem them at yard sales for cheap but depends on the shape they are in. The advantage is these have an 8 inch opening (i.e. easy to clean and put liquids in/out like a plastic bucket but practically impervious like a glass carboy). I hate dealing with the small neck on carboys and always worried I am gonna drop the thing even with the carriers. Only issue is fashioning a top for airlock or sealing. I have been using press and seal for a couple years now (with a 8 in tubing clamp) with no infections. The P&S lets CO2 out since it is semi-permeable but doesn’t let the nasty’s back in since that is what it is made to keep food from spoiling. The only problem is if your fermentation temperature gets too high (>75F) – the P&S will rise like a conehead (it stretches pretty good but only so far) and eventually pops. I am guessing you can find 8 inch plastic lids that would work though if you are not comfortable with P&S. I originally used a drilled 8 inch fernco cap but was worried the rubber would impart off flavors (even though it was non contact) or worst case poison me (who knows what that stuff is really made of) – so I switched to the P&S pretty quick. All in all the best $140 I ever spent for homebrewing equipment.

  2. Hopshead

    Here Here! I have gone full circle with plastic buckets. As with most people, it was in my starter kit and I used it extensively with good results. Then the more I read, I decided I need to go with glass. Then after making beer in glass fermenters, my daughter was born and I almost immediately decided, I could live with broken glass, but not her. So I went to better bottles and loved them until they cracked on the bottom, (not sure why). Now I am back to plastic buckets and I after all my trials and tribulations with different fermenters, I don’t know why I really switched away from them. Sure oxidation will be an issue, but I brew 100% ales that don’t require longer than a 2 week primary, and I agree with your assessment that you won’t loose a batch to bacteria “in the microscopic scratches.”

  3. I agree with you. I’ve used both plastic and glass and I always go back to plastic. The only time I do not is when I want to age it for awhile. Plastic buckets are easier to clean, the scratches myth is just silly, and it is easier to move/store the buckets.

  4. floodx
    Love the idea of the stainless milk cans, but wouldn’t fermenting in corny kegs be just as good? And for $140 you could get 4 cornies! And they have all the built in hardware for transfering beer aspectically with CO2 pressure.

    I am not sure if Press and seal works the way you think. I would not expect it to keep airborne microbes out of the beer beer. Its pore size it to large for that I think. I would retry your drilled out lid, but get a food grade 100% silicone rubber gasket. Then there’s no worries about rubber toxins or what have you.

    Great ideas though. Cheers to being innovative.

    BREW ON!

  5. floodx

    The cornys are aluminum or steel – not stainless – not sure about fermenting in aluminum? guess it couldn’t hurt other than I presume that it is a much softer metal and would scratch like plastic somewhat easily? And since cornys are cheap because most of the ones you can find are used they may already be scratched? Plus I find even the cornys (what 2-3 inch opening?) hard to get liquids in/out of and much harder to clean that my milk can.

    Yeah the other brewers make fun of me too when I show em the P&S fermenter – but it just works – been using it for 20-25 batches no infections – and I am not the cleanest brewer. The stuff is made to keep microbes out of food so why not a fermenter? I haven’t really thought about it until now but technically I could apply a thin anti-microbial product on top of it too – I don’t think that it is sufficiently liquid permeable according to a google search.

    Just an alternative – price is always an issue – I wish I could afford the 10 gallon can…

  6. I looked at the website and the 10 Gall0n was $140, I thought.

    BTW, Corny kegs are stainless steel. Cleaning them is very easy with PBW and a quick soak. How do you think the big breweries clean out actual half barrels with the little opening on them? I think for your money you should give cornies a second look.

  7. Richard Mooney

    I have to agree with you on the scratches point – micro-scratches? What?! Never heard of anything going wrong with plastic containers. Add to that the fact that a long enough sterilization is going to kill pretty much anything, and you’re sorted.

    The great thing about plastics is that they’re great for the home brewer / winemaker – think of all the stuff you get from the store that comes in big plastic jugs! Cheap fermenters!

    Having said that, a lot of these containers are not transparant, which makes them impossible to use for clearing – great for primary fermentation, but you really need to be able to see your wine to clear it.

  8. I’ve always used buckets. My biggest problem with the glass, or better bottles is the racking? God F*(&ing damn to I hate to rack. I just basically use bottling buckets for everything. I just drill the 1 inch hole, and put the bottling spigot in, presto instant sample taking for og reading, and I just hook up a 3/8 tubing and bam into the bottling bucket it goes.
    Buckets will last forever, and I just use corny’s to age anything over a month.

  9. I quit using carboys years ago for large (13gal.) food grade plastic. I open ferment and have not had a contaminated batch yet. I’ve got a couple of these fermentors that I use now and both have spigots in them for easy transfer. Carboys or better bottles, I wouldn’t go back to cleaning those and having to siphon. Finally, if I need to keep the beer over a long period of time I simply transfer to a corney. Couldn’t be easier.
    Beer Diary…

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