You are shopping Northern Brewer US shopping site, to view our Canadian shopping site - Click Here

Siphonless Big Mouth Bubbler® - Ported 6.5 Gallon Plastic Fermentor


SKU# 41436

Standard Shipping Rates Apply to this product

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

Siphonless Big Mouth Bubbler®

More Views

  • 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
248 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
Absolutely awful product
The lid was impossible to keep sealed. Apparently the design for the lid changed recently, and it USED to be a screw on lid. This product would be five stars if it still had a screw on lid (the bubbler has threading for it still), but instead it has a lid that is akin to a standard bung. This was literally impossible to keep sealed. I tried duct tape, setting four heavy cans on top, and nearly glued it shut before dumping out the batch of amber ale I foolishly put in it, and promptly throwing the big mouth bubbler out in the trash. A waste of money on the product itself, and the batch of beer I put in it. Please save yourself the money, time, and frustration, and find something else!
February 27, 2017
9 months ago
I purchased four big mouth bubbler's on Northern Brewer's recent sale. I'd been debating back and forth between the BMB and another similar plastic fermenter. After doing a good bit of research, I pulled the trigger on the BMB based largely on the sale price. I was super excited to get them in and, based on many reviews I had read, was ready to make a couple easy modifications to the screw ring top in order to get a proper seal. Much to my dismay, the BMB's came in with a new and "improved" lid design. I'm glad the folks in R&D are aware there's a problem and are working to solve it, but I can't believe this new "improved" lid is any better than the old screw ring lid. The new lid, uses a silicone friction fit seal that fits between the outer lip of the lid and the inner lip of the bottle. This is a terrible design. There's no way, short of taping the lid down or weighting it down to get it to stay in place. The solution is easy, use a combination of the new and old lid systems...use the seal from the new lid in conjunction with the screw ring from the old lid (the threads are still on the bottle to screw on the lid) to hold the lid down...voila...perfect! Please, Northern Brewer, bring back some of the old screw rings for the lids so we can hold these new lids in place. I know you say it's ok, but I'm just not comfortable having the lid of my fermenter completely loose! Were it not for the lid issue, I'd give this product five stars...as it is, its only one. I also have to say, while I'm usually more than impressed with NB and their service, this lid issue really makes me question them...what kind of a company puts out an obviously flawed product with no solution for the consumer?
September 29, 2016
Response from Northern Brewer
Customer service is always happy to help with any issue. Some sanitizers, like star san, will call for air drying but many skip that. If you allow the item to dry, even by using a paper towel, it will not be as slippery and hold in place very well. A 2-3 pound weight on the lid would also help hold it down in place.
November 21, 2016
Northern Brewer
Bring back the screw top. The push down lid is poor design and the idea of using tape, etc to hold the lid in place is a bad idea. You are asking the customer to fix your problem. Northern should provide the mason jar type screw down at no charge to make this right.
August 7, 2016
Response from Northern Brewer
We ask nothing of anyone, except that everyone have awesome beer. Sorry to hear you are experiencing difficulties, customer service is reaching out to you!
November 21, 2016
Northern Brewer
poor seal
This is one worthless fermenter. It may work for a secondary where there isn't much gas buildup but it is totally worthless as a primary fermenter. I totally wasted my money. I contacted NB and they suggested inverting the silicone seal, which I did, but it wasn't much help. They said some people are putting a weight on the lid. Why do that? Maybe they should sell a brick with each one? A total waste of time that could easily be corrected with a screw type lid instead of the lid where you are supposed to jam it down.
October 6, 2016
Response from Northern Brewer
Customer service is always happy to help with any issue. Some sanitizers, like star san, will call for air drying but many skip that. If you allow the item to dry, even by using a paper towel, it will not be as slippery and hold in place very well. A 2-3 pound weight on the lid would also help hold it down in place.
November 21, 2016
Northern Brewer
Great container, HORRIBLE lids
I have the old style with the screw on lids and they worked good for a while. The threaded cap would swell up and then not hold any more. I since bought these new style with the redesigned lids. They are awful. The cap is a friction fit and won't stay down. I've had to tape the caps on to make sure my beer is sealed and makes use of the airlock. I can't believe this wasn't noticed before sale.
Shouldn't have to tape the cap down.
Shouldn't have to tape the cap down.
February 21, 2017
9 months ago
Bad design, poor manufacturing
The lid design is awful. It constantly pops out when you first put it in. I think it is from the release of gas from sanitizing solution bubbles popping/ beer aeration bubbles popping. So you have to constantly push it back down. Pushing it back down makes the pressure suck water in from your air lock making you need to refill it multiple times and risk contamination. Why not a screw on lid?

Also, the bottom of the INSIDE of the carboy has rough irregularities from the manufacturing process which make you have to clean it more thoroughly. Also this makes sanitizing it more dubious.

This product was supposed to make the process easier but is an even bigger pain to use. I bought one of these and a 5 gal and it was a total waste of money when I already had some perfectly good normal carboys.
January 16, 2017
10 months ago
Love it, but with issues.
Love the BMB, makes racking much easier. However, with aggressive fermentation, the lid will "pop-off". this happens ALOT. I solve this issue by taping the top down.
February 22, 2017
1 year ago
6.5 Gal. BMB
After reading all of peoples' reviews...both positive and negative on the BMB I went ahead and bought one. After a couple of brews, here are my thoughts:
1. You must use the 6.5 gal. BMB if you are doing a 5 gal. batch. There must be adequate head space. I sanitize my lid and push into place with no problem.
2. Take a piece of #400(fine) sandpaper and sand both sides of the BMB where the hole is drilled for the valve. My had burrs on both sides. Once the burrs are removed, there are no leakage problems. Finger tighten only. Do NOT use coarse sand paper.
3. After sanitizing the valve, I would not use it to take gravity samples. You leave wort in the valve for contamination to occur. Get your gravity samples with a sanitized thief thru the top. Only use the valve to pitch to another body.
January 4, 2017
Do not miss out on owning this because of "bad lid" reviews
I used a little packing tape to secure mine on once I saw the issue during my first brew. After this, the lid stayed in place without anything anchoring it to the fermenter. Several people also remove and flip the rubber seal upside-down and this resolves the issue. For $40 this product works great. I don't need a siphon anymore so there is less to clean and sanitize. I've made a total of 18 brews used through these fermenters and they all have turned
out really well. The old style lids for these would never seal correctly and this new style lid (once broken in) has completely resolved the issue.
Black Metal Farmhouse Stout clone and a hard cider fermenting away
Two IPAs bubbling away
May 16, 2017
It is lighter and easier to carry than a glass carboy. The spigot is still in the trub zone and i had to siphon the beer. Not an issue compared to the "lightness of being". Will have to get the infuser for fruit addition.
July 27, 2017
4 months ago
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 66 questions Browse 66 questions and 156 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: Many herald the universal lid as a great improvement over the past screw on lids that did not have a gasket. The lid is essentially a large stopper so has its drawbacks. For instance, many love using star san sanitizer but skip the drying step that the manufacturer recommends. Star san is quite slippery when wet and this can lead the lid to push up easily. With a dry lid, push it down and twist and the lid should be super tight. Anyone experiencing an issue is encouraged to contact customer service to find a resolution!
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.


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.
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.
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 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.
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.
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 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?
D 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.
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.
What are the dimensions for the 6.5gal size?
J A on Jul 20, 2016
BEST ANSWER: The 6.5 gallon fermentor has a height of 21 3/4 inches, including the original screw cap and port lid insert. If you are using the newer universal lid, the height would be reduced to 21 3/8 inches. The circumference is 35 inches, and the diameter is 10 3/4 inches. The spigot will protrude 1 1/2 inches from the side. Check out this link from the manufacturer http://bigmouthbubbler.com/design/
What size spigot does the BMB use?
David C on Jul 16, 2016
BEST ANSWER: It's the standard spigot used on the bottling buckets, SKU 40794. I uses a 1" drilled hole, and can be used with 5/16" or 3/8" siphon tubing. -Mike W, Northern Brewer
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.
Is there any reason this should not be used for white wine?
R Z on Jul 1, 2016
BEST ANSWER: No reason, just cover it up during fermentation.....

You may also be interested in:

Please wait...

Your selected product has been added to your Cart.
Continue shopping
View cart & checkout