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Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor


SKU# 41436

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The most helpful fermentor ever invented just got even better. Less effort. Better, clearer beer. Don’t just cut out the hassle of cleaning, cut out siphoning altogether! Porting this revolutionary fermentor makes transferring as easy as the turn of a valve. No extra equipment, no extra cleaning, just a sanitized fermentor.

Included: Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor, spigot, single-port universal lid.
Required but not included: Small Universal Stopper & airlock. Add to cart to view stoppers and airlocks.


Availability: In stock

Get it in Ashburn by Thu May 24.
Siphonless Big Mouth Bubbler®

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  • Siphonless Big Mouth Bubbler®
  • Siphonless Big Mouth Bubbler® - Lid
  • Siphonless Big Mouth Bubbler® - Trub Closeup
  • Siphonless Big Mouth Bubbler® - Trub Closeup
Product Details

The Siphonless Big Mouth Bubbler® Plastic isn’t just easier to use. It’s better for your beer. Fight oxidation and contamination by keeping your fermentor closed for transfers. Never open the lid to insert an auto-siphon, just turn a valve and you’re set. Best of all, you’ll have clearer beer. Gently rack liquid from the spout into secondary without disturbing the trub.

Make your brew day easier and your beer better with the siphonless Big Mouth Bubbler®.


  • Ported Big Mouth Bubbler® Plastic Fermentor
  • Spigot
  • Single Port Universal Lid

*The new Big Mouth Universal Lid (included) fits all Big Mouth Bubbler® Fermentors. The Big Mouth Bubbler® Universal Lid is just like a traditional carboy bung, only bigger! Just as easy to sanitize and set in place too. Ribbed silicone rings ensure a positive seal to keep out pests, while the non-threaded design allows the lid to move preventing an out-of-control fermentation from dangerously pressurizing your fermentor.

The optional Dual Port Lid allows for the use of a temperature controller probe. The ThermoStar Dual-Mode Digital Temperature Controller with optional 12" stainless probe ensures precise and repeatable fermentation temperatures!

Lid ports work with our Small Universal Stopper or a standard 6.5 rubber stopper.

Important Note: Do not fill any Plastic Big Mouth Bubbler® fermenters with very hot liquid - temp should not exceed 140 degrees Farenheit (60 celcius)

*Pro Tip: Save your box and use it as a cover for your fermenter!

BIG MOUTH BUBBLER® Product Specifications:
Capacity:5 gallon6.5 gallon
Height (w/lid, closed):22"23"
Fermentor Material:PETPET
3.8 / 5.0
338 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
I am glad I did not pay for this it came free with purchase of two kits not very sturdy and like many others have noted the lid is a joke this is the first bad review for anything from northern brewer did the job but not worth the money
May 14, 2018
1 month ago
Bigmouth siphonless.
It makes racking to a secondary fermentor or bottling bucket effortless.The bigmouth also makes cleaning much easier.
May 11, 2018
1 month ago
Wouldn’t get another one if it was free.
Well, all the other reviews were right. I picked this up a couple of weeks ago when they were being offered for free. It holds liquid, thats the only positive thing i have to say about it. I knew about the lid problem so i taped it with gorilla tape. Well my fermentation with caribou slobber was so good, it pushed the tape off. Now i have a tile and 20lb weight sitting in it. Hopefully that holds and my batch did not get ruined. Great idea, would be perfect with the threaded lid. I guess the inly use I’ll have for this now will be a bottler. Had I to do it over, I would have asked for another bucket instead of this junk. Glad it was free at least.
This is the only way to keep to keep the lid on.
This is the only way to keep to keep the lid on.
May 9, 2018
1 month ago
Not bad but not great.
Overall it seems like a pretty good vessel for fermenting. My only complaints are that it didn’t come with a rubber plug to place the airlock or blowoff tube in so I had to go out and get one. As others have mentioned in their reviews thatid doesn't stay on so you have to tape it or put something heavy on it to keep it down. A mild inconvenience but it’s worth noting. I got it free when I bought two kits so if I had paid full price I would probably be a little more mad about its downfalls.
May 8, 2018
1 month ago
I love it. It is easy to clean and easy to use. Definitely recommend it!
May 8, 2018
1 month ago
Why didn't somebody think of this before?
This is my second Big Mouth and I am thrilled with the quality and how much easier it is than my glass carboys, that I have been using for over twenty years.

The big mouth allows for easy cleaning and pouring of the wort without need of a funnel. The builtin spigot eliminates the need of an autosiphon and makes easy work of transferring to secondary and to bottling.

Highly recommended. Why did it take so long for someone to think of this!
May 8, 2018
1 month ago
Multiple Uses and All Successful for me
I was looking to add to my brewing equipment and took advantage of a sale to acquire the Big Mouth Bubbler at no cost. I was concerned when I read the reviews that mentioned difficulty with the lid, but I can say that I have used the Bubbler as a Primary and Secondary Fermenter as well as a Bottling Bucket and have had nothing but success and no issues with the lid or the port. No blow offs and no eruptions and no leakage.
May 8, 2018
1 month ago
Well spent money !!!
Wow... sooo much easier to brew 5 gal batches now.
Extra room for foaming batches. Real easy to clean, and no siphoning !!! Yaaayyy !
May 6, 2018
1 month ago
It works fine
I read all of the reviews AFTER I ordered this unit.(Also ordered the harness). I made my first batch and rigged up hold downs using wire over the bung. It worked fine. I’m on batch #2. Same setup same results. Improvising is part of homebrewing. The port really helps when bottling.
April 30, 2018
1 month ago
Top sucks (blows?).
Top blows off very easily. Get a screw top, if available. Otherwise, it is great.
April 15, 2018
7 months ago
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Browse 70 questions Browse 70 questions and 165 answers
I've seen different statements that this doesn't fit a 6.5G ported BMB. Northern has said No, owners say Yes. Any final response? Also, has anyone used with a fermwrap underneath the holder? It wraps around about 80% of the circumference.
A shopper on Jan 7, 2017
Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor
Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor
Plastic Big Mouth Bubbler® Harness
Plastic Big Mouth Bubbler® Harness
BEST ANSWER: Northern brewer brewmsater here! It fits perfectly, the spigot should not be in the way.
Will Bubbler ever stop making the horrendous "universal" lids?
J O on Sep 7, 2016
BEST ANSWER: I had the same issue with the universal lids and tried allowing the star san on the lid to dry before putting it on the bubbler but had mixed results. I went to the local sporting goods store and purchased two 5-pound barbell plates for less than $4 each. One plate easily slips over my 3-piece airlock and securely seats the lid. Works 100% of the time and no more concerns about the lid pushing up and allowing the beer to become contaminated. It probably isn't what customer service would recommend but it works like a charm.
Does the Big Mout Bubbler have volume markings?
A shopper on Jun 20, 2017
Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor
Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor
Big Mouth Bubbler Plastic - 5 Gallon
Big Mouth Bubbler Plastic - 5 Gallon
Big Mouth Bubbler® EVO 2 - 5 Gallon Glass Fermentor
Big Mouth Bubbler® EVO 2 - 5 Gallon Glass Fermentor
Big Mouth Bubbler® EVO 2 - 6.5 Gallon Glass Fermentor
Big Mouth Bubbler® EVO 2 - 6.5 Gallon Glass Fermentor
Siphonless Big Mouth Bubbler® - Ported 5 Gallon Plastic Fermentor
Siphonless Big Mouth Bubbler® - Ported 5 Gallon Plastic Fermentor
Big Mouth Bubbler® EVO 2 - Siphonless 6.5 Gallon Glass Fermentor
Big Mouth Bubbler® EVO 2 - Siphonless 6.5 Gallon Glass Fermentor
Big Mouth Bubbler® - 6.5 Gallon Plastic Fermentor
Big Mouth Bubbler® - 6.5 Gallon Plastic Fermentor
Big Mouth Bubbler® - 5 Gallon Plastic Fermentor
Big Mouth Bubbler® - 5 Gallon Plastic Fermentor
BEST ANSWER: Yes, the Big Mouth Bubbler Plastic does have indentations as markings but does not have numbers 1 - 5 or .
You have to count them to determine at what level you are at.
Are the ported 6.5 and 5 gallon big mouth bubblers made of plastic or glass?
M A on Dec 30, 2015

We offer them in both versions:


However, we are currently sold out of the glass version.


has anyone used the siphonless wide mouth plastic bubbler for brewing kombucha? Concerned about the acidity of booch and the plastic interactions. thank you
H O on Jul 12, 2016
BEST ANSWER: These fermenters are made of PET plastic and will not leach anything into the kombucha. They are regularly used by people to make it.
Does this hold a better seal than earlier BMB lids? I have a version 1 6.5 gal and I quit using it because the beers all tasted slightly off and I never saw action in blowoff so there had to be a leak. Switched back to old faithful glass bubbler and action like crazy.
E M on Feb 28, 2016
BEST ANSWER: This comes with the same lid that plastic big mouth bubblers use. When tested, the lids can seal, so if not sealing, there may be an issue with one. There is a universal lid which seals better. All my plastic ones seal well enough as needed. An imperfect seal can only result in off flavors if the beer sits in it for too long - if you transfer within a week or two to secondary, then you have no concerns.
Is it a ok idea to use the spigot to get a sample for a hydrometer reading?
A shopper on Jan 24, 2017
BEST ANSWER: I think so but I would use a refractometer because it only takes a few drops and it will save your beer esp. if you take multiple samples over time for gravity readings. I spray inside the spigot with star san before and after taking the sample. I also use a clean sanitized bristle brush to make sure the spigot is clean. I haven't had any problems. But I use a refractometer and not a hydrometer.
Does the fermenter have print marks in liters or gallons?
A shopper on Feb 25, 2017
BEST ANSWER: There are technically no indicators other than the lines on the side, but they are marked at the gallon levels. There's 6 hash marks, one at each gallon level. Hope that helps!
Is there any reason to use an airlock with this for venting CO2 versus running some tubing through the stopper and venting the gas into a bucket of water?
David S on Sep 9, 2016
BEST ANSWER: I actually use both methods, depending on how I anticipate the rate of fermentation. For most of my typical beers, starting out with OG of 1.040 or so, I use a single hole stopper and an airlock. I like to brew an Imperial Stout, which always starts out strong, so I use a blow off tube and seal between the tubing and fermenter cover using about 1? vinyl tubing into a container of sanitizer. Sometimes, I still have a mess to clean up, but that is a fermentation issue, not a fermenter issue. The part I like the best with the optional top is the two ports so I can put the air lock or blow off tube in one port and a thermowell in the other through a 1 hole stopper. Lastly, I am really liking the spigot in the fermenter. I do always remove it between batches and clean it thoroughly, and when I use it again, I install it and check it with a complete fill to make sure it will not leak.

Jim Schultze
Would this be good for making red wines?
H E on Sep 5, 2016
BEST ANSWER: Yes, this would be a great primary fermenter for red wines. I would not recommend using it for secondary fermentation or ageing as it is plastic and will allow too much oxygen exchange, as would any plastic vessel.
Can you use the spigot for filling the beer bottle or should I stick with a symphon tube?
A shopper on Jan 27, 2018
BEST ANSWER: Absolutely. I've used the the spigot method in both primary and secondary fermentors. I would suggest when transferring beer through the spigot, whether it's moving it to the secondary Big Mouth Bubbler, to a bottle or a Cornelius keg, watch for any hop particles that begin to appear in the clear transfer tube. The hop particles will pass through the spigot but it will make your beer less clear.
Are there replacement spigots available? I have one that split inside and it has a small leak.
A shopper on Apr 29, 2017
BEST ANSWER: Yes. The spigot is called, "Fermenter's Favorites® Bottling Spigot for Bottling Bucket", and sets into place with by hand tightening. Pay attention to the gaskets and install them in the correct order for a leak free connection.
I have yet to purchase this item, but was wondering if I purchased the two port lid, could I use it with my Johnson temperature controller? How would I keep a tight seal around the probe wire running through the hole in the bung? Would I just need to use a thermowell?

Thanks in advance for help.
J O on Aug 21, 2016
BEST ANSWER: Sounds like you?re the kind of person that likes campground engineering? projects. Someone after my own heart ;-)
The port lid uses a #6.5 stopper. If you cut a solid stopper in half lengthwise, run the Johnson wire to your required depth, and then wrap some tape around the assembly to hold it together, that might work. Once you push it securely into the port, the pressure should seal the rubber stopper around the probe wire sufficiently. The Thermowell is only a $15-$30 solution depending on where you can find them.
What I do is simply tape my temp probe to the side of my fermentor, and then tape some foam insulation material over the probe. It?s not very sexy, but it works pretty darn well.
Can this be used as both a primary and secondary?
O L on Apr 13, 2016
BEST ANSWER: I have definitely used these for both primary and secondary fermentation, but the one concern about using a 6.5 secondary in general is the amount of head space left in the container (assuming you're brewing 5G batches). I haven't experienced any oxidation problems, but I have gone back to using my old 5-gallon glass carboy for secondary, when I do go to secondary. BTW, I am thinking about getting a 5-Gallon bubbler as a secondary fermenter.
Can I please get the dimensions of the Bubbler
J S on Jan 18, 2016
BEST ANSWER: Without spigot or airlock installed I get 9 1/2" diameter standing 21 1/2" high. WITH spigot and airlock (aka, 'in use') I get 12 1/2 " diameter and standing 26" high with the three-piece type of of airlock. Hope that helps.
what is the premary stage and secundary stage?
Pablo A on Feb 1, 2017
BEST ANSWER: Primary fermentation is the first 1-2 weeks after you add the yeast to the wort. By that time most of the visible activity has resolved with few bubbles in the air lock and a pretty flat head if any. there is also a layer of "sludge" on the bottom of the carboy. This is pretty much spent yeast. If you leave the beer sit on this it can lead to off flavors.
When you transfer the beer into a second carboy and leave the "sludge" behind you are in secondary fermentation. You will get an up tick in activity for a day or two. You can leave it in secondary as long as you like depending on style. For lighter beers another 1-2 weeks is enough, for my Russian stouts I usually go 3-4 months in secondary and if I get an appreciable amount of "sludge" in secondary I'll do it again and go into tertiary fermentation.
My second bubbler will not seal at the port. The seals appear to be fine, but I have a constant drip. Suggestions?
J A on Sep 2, 2016
BEST ANSWER: Clean the burrs off the drill hole. Then there should be two gaskets on it, one on each side of the fermenter wall itself. Fill with water and loosen the fittings up until it leaks a bit and then tighten it up just enough to stop the leak, if any. Over tightening is just as bad as under tightening. You warp the gaskets if you tighten too much.
Can I go straight to keg from primary fermentation with this? Or is it still recommended to transfer to bottling bucket first then to keg from there? Looking forward to streamlining the process however I can...thanks.
E D on Jun 22, 2016
BEST ANSWER: The whole point of the spigot is so you do not have to open the carboy to siphon to a bottling bucket or keg. This reduces exposure to nasty bugs that will spoil your beer.

I just elevate my carboys, connect a hose, and open the spigot to drain straight into my keg.

You shouldn't transfer your beer to a secondary container just to transfer it again to a keg. If you are doing this for clarity reasons, I recommend you transfer your beer straight from your primary to the keg and then chilling it (cold crash). The first pint you pout will be hazy (dump it) because all the trub particulate settled to the bottom during cold crashing.
Looks great and will probably order one. Maybe I'm not looking at this right, but I'm wondering about possible contamination of the spigot while my beer is fermenting. Thinking that the inside of the spigot is exposed to air for 2-3 weeks, do I need to clean up into the spigot right before I bottle?
Tollie L M on Jan 1, 2016
BEST ANSWER: Hello, I have used both the 5 gal and 6.5 gal with spigots and have not had a problem. I would imagine as long as you thoroughly clean the spigot before adding the beer (I soak it in SanStar) and not use it while fermenting (use a thief to sample), it should not get contaminated. The only time I use it is to transfer from the primary to secondary, and for bottling. If you are concerned with exposure to the air, I suppose that after you clean the spigot, you could wrap a plastic bag around it and secure with a rubber band. Just don't use it until you are ready to transfer. I recommend getting the bubbler. So much easier to clean than the carboy. Easy to see and the spigot makes tranfer so much easier than the siphon.
Will the BrewJacket work with this fermentor?
F E on Dec 31, 2015
BEST ANSWER: Sorry, I don't have a brew jacket and can't answer the question about it fitting the Big Mouth Bubbler. The circumference of the BBB is about 34 1/2 inches. The height of the wide part is 18 inches or so. Not sure if that is helpful.
What size tubing is needed to attach to the port when transferring to secondary?
Dorian R on Nov 28, 2015
BEST ANSWER: The tubing for this spigot is the [3/8" ID Siphon Hose](http://www.northernbrewer.com/3-8-id-siphon-hose).
Can you direct bottle at end of fermentation with this unit?
Michael L on Nov 11, 2015
BEST ANSWER: It depends on how you prime your beer for carbonation. If you use the sugar drops in each bottle, then you could rack directly from your fermenter. However, if you add priming sugar to the batch, you're going to stir up all of the spent yeast and grains that have collected below the spout mixing in the sugar. To me, the thing that I love about the Big Bubbler is that I can syphon off all my beer without disturbing the trub. If you're in secondary and have eliminated almost all of the trub in primary, this wouldn't be as big an issue.
Do I need to disassemble the spigot after each use for cleaning/sanitizing?
O K on Nov 1, 2015
BEST ANSWER: It is advisable to disassemble the spigot and clean it after each use as well as sanitize it before each use.
Im getting ready to purchase the big mouth bubbler ported and want to buy new tubing for the spigot and Im not sure what size to use. thanks
B B on Oct 21, 2015
BEST ANSWER: The one you said to get worked fine
Can someone explain why this is better than a bucket? Beside the obvious visual appeal of seeing the fermentation in action...
L M on Oct 2, 2015
BEST ANSWER: A bucket is opaque

so you can;t see the product. The opening is also wider

not by much

but still. That is the main benefit but does prove useful information. I would also consider the seal on a BMB to be better than a 6.5 bucket.
Will this work for a wine kit? Is it big enough?
J E on Oct 1, 2015
BEST ANSWER: This fermentor would work great for a primary for a 6 gallon wine kit. For a secondary

you would want a 6 gallon carboy. We use the 6.5 BMB as a primary in our wine equipment kit

which was developed with the wine expert Tim Vandergrift.
Any thought of making a 2.5 or 3 gallon BMB in the future?
A shopper on Dec 24, 2017
BEST ANSWER: I use the siphonless BMB exclusively, I have three 6.5 gallon fermentors. It makes transferring beer to the secondary so much easier and results in a clearer beer in the end. I suggest getting the carry strap, it's a little difficult to move around without one.

Home brewing since 2010.
Levittown, Pa.
Does the threaded lid that comes with the little big mouth bubbler set also compatible with your Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor?
A shopper on Dec 13, 2017
BEST ANSWER: I'm pretty sure the original plastic fermentor has a smaller opening than the 6.5 gal. glass fermentor. The top of the glass fermentor is not threaded either. So the lids are not interchangeable (though I really wish they were).
I got a Brett infection in my latest BMB brew. Is this thing salvageable or should it become my permanent wild beer tank? What's the best way to sanitize it after infection? Can I use bleach on it without future chlorophenol issues?
Shelby H on Aug 15, 2016
BEST ANSWER: The fermenter is not lost but will require extensive cleaning and sanitation to salvage. I recommend a long soak with a PBW solution then fill the fermenter with a Star San solution and soak for at least a few hours, making sure to cover the entire surface of the fermenter. This should kill off any remaining Brett. I would avoid using bleach.
Is plastic ok for a secondary fermentor?
Kent A on Jul 30, 2016
BEST ANSWER: I only use mine for primary fermentation.

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