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FerMonster Carboy - 7 gal.
Accessories for your Fermonster
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The Fermonster is a brand new fermenter designed specifically for fermentation. MoreBeer! gave product feedback for over 2 years of development and we think they nailed the design. The large lid allows for easy filling and makes hop or oak additions a breeze. The smooth sides are fantastic for sanitization - no ribs or texture to collect yeast or bacteria.  The large 7 gallon size was designed to provide ample space for fermentation and you'll find the molded in volume markers super handy for accurate filling. The punted bottom allows sediment to collect to the sides so that you can siphon liquid from the center.  Because they are made from vigin PET plastic they nearly unbreakable and a lot safer than similar glass carboys. Also notice the conical top which reduces surface area if you plan to store beer or wine long term.  

Made from heavy PET plastic, the same material used in 2 L soda bottles, which is nearly impermeable to oxygen penetration.  Due to the thickness of the material and the overall geometry the Fermonster does not require ribs or dimples for stability.  That results in a super smooth interior surface that reduces yeast and sediment buildup making it the easiest to clean, most sanitary PET carboy on the market.  The huge 4" opening makes filling a breeze, and cleanup is as easy as wiping down the inside.  The 7 gallon volume is a monster of a fermenter, reducing blowoff issues seen with standard 5 and 6 gallon carboys. Fermonsters are easily moved by hand or consider using our Carboy Carrier for even greater ease of use.

These fermentors are completely air-tight and the lids sealed tight with an O-Ring.  Additional O-Rings and Lids both with and without holes are available for purchase, see our You Might Also Need items below.


  • 4" inner diameter wide mouth carboy - easy to clean!
  • Food grade PET plastic construction is nearly impermeable to oxygen penetration
  • No hard to clean dimples or ribs
  • Volume Markers at 5, 6, and 7 Gallons
  • Punted bottom
  • O-Ring and Lid with one hole is included (Fits #10 Stopper)
  • Additional O-Rings and Lids available
  • Weight: 1.5 lbs
  • Temperature Limit: 140° F
  • Height: 20.9 inches
  • Diameter: 11.3 inches
  • Completely taste and odor free
  • Perfect for Beer, Wine, Cider, Mead, Kombucha or any other fermented beverage!
Item # FE255
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - In Stock
Weight 2LBS
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3.7 / 5.0
15 Reviews
5 Stars
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1 Star
Great product, just some things to consider
I like the wide mouth which is good for adding fruits and other things without trying to shove it in. The only issue I have is that the O ring is slightly larger than the seat so much so that it doesn't fit right inside the lid that you don't get a good seal. I just had the O ring fall into my chilled wort, lucky thing it was sanitized (I didn't even bother fishing it out since it fell to the bottom). Lastly, (more of a caution) if you ferment outside an enclose fermenter, there is a possibility of mold/dust/bugs, etc. growing inside the spigot, so I always use a siphon now.
May 24, 2018
Very easy to use and easy to clean. Sometimes lid is hard to remove but does not take away from quality and ease. I plan to plan to buy another.
March 29, 2018
Others are better
Couldn't get the lid off without squeezing the fermentor. I turned the lid and it was so tight that the 6 gallons of beer in it spun with the fermentor on my basement floor and scratched the bottom badly. I had to squeeze the fermentor really hard to get it off and that made me nervous because its a pretty thin plastic. The lid is obviously a problem since now they have a tool to help you remove it. The large opening is nice but I can't see this lasting long at all.
February 24, 2018
My best fermenter
Over the last 9 years of brewing, I have gone from glass to plastic fermenters. Have a number of better bottles which work well, but cleaning can be a pain at times and a blow off tube is necessary on almost all ales. Have a Spieidel which I like and the built in handles work well plus is large enough to not need a blow off, but have continued to have problems with leaking from the spigot. The Fermonster has solved those problems. No need for a blow off tube, and cleaning is a snap. The sprayer on the sink gets most of the crud off, and I use a microfiber cloth and PBW. I feel better being able to scrub the inside rather than just letting the PBW soak. I use a Brew Hauler strap which works great. The gallon markers on the outside are difficult to see, so I outlined them with a Sharpie and that helps a bunch. The only downside is the seal on the lid. The O ring is properly seated, but sometimes it works and sometimes not. No big deal as it does not affect the fermentation. Have seen on the manufacturers website a handle for tightening and loosening the lid, but have not found it on More Beer or anywhere else.
Overall, satisfied with these and feel they are the best option out there.
August 27, 2017
Only lasted five brews!
Glass carboys, no problem, I've lost track of how many brews. FerMonster...lasted five brews before the bottom cracked (never miss-handled or dropped it) and it leaked out into my fermentation fridge. I was able to save about half of the brew by transferring into a glass carboy. Cheaply made product, I highly recommend NOT buying. Stick with glass or stainless, or even buckets!
August 9, 2017
Fantastic upgrade
I purchased 4 of these to replace the buckets I had been using for the last 7 years. The 7 gallon size is perfect for 6 gallon batches with enough headspace for the krausen. The markings are accurate. As others have said, the lid can be very difficult to get off when you put it on too tight. I have found that barely hand tight is enough to get a seal with the o-ring without requiring hulk hands to remove it. The large opening is fantastic for everything from pitching yeast and dry hopping to cleaning and drying. For the price, this fermenter can't be beat.
May 23, 2017
Not a Fan...
I've been using a Speidel over the past year and have been very pleased with the extra head space and the durability. I was hoping for the same with the FerMonster, but it's just not there. It feels cheap like I'm holding onto a an empty two liter bottle, the measurement marker is not accurate, the rubber gasket doesn't fit to create a seal, and the cap cracked on only the second time using it for a primary. I'll stick with Speidel fermenters from now on.
May 21, 2017
Great fermenter.
So I picked one of these up a while back and have brewed a few batches with it and I am impressed.
It's plastic, so no worries about dropping it and bleeding out. Smooth sides make for easy cleaning. The punted bottom really does make siphoning out clear beer much easier. Good seal on the lid, haven't had any problems with it.
My only downside to this is the side of the opening. Yes, it's much larger than a regular carboy but it could be a wee bit bigger. I'm not a "sun's out, guns out" person but my arm is a bit bigger than the opening. I can still reach the bottom and clean this with a cloth but I have to jam my arm in. If you're a pro cyclist with those skinny T-Rex arms, this will be perfect.

All in all, I'm super happy with this thing and wouldn't hesitate to recommend it.
January 29, 2017
Killer fermenter!!
Call me very impressed just got done kegging an ale and it took all of 20 seconds to perfectly seat my auto siphon in the middle of the Fermonster. It also stayed seated! It was the first time ever that not one touch of yeast or hop matter made it in my keg. I guess the Spigot would be cool too on them but not needed ! I will be buying more of these fermenters. The only thing I didn't like is some imperfections on the seam.
October 23, 2016
The volume markings have to be highlighted with a sharpie to see them. Just finished a 1.050 beer, vigorous fermentation, absolutely no air lock activity. Put the lid on hand tight, after a day, tried to adjust it to see if it was not tight enough and could turn it at all. Sorry I bought this.
September 26, 2016