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Fermonster Carboy - 3 gal.
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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 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.

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
  • 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: 14.6 inches
  • Diameter: 9 inches
  • Completely taste and odor free
  • Perfect for Beer, Wine, Cider, Mead, Kombucha or any other fermented beverage!

Please note: the pictured #10 Stopper (FE470VS) and three piece airlock (FE370) are not included.

Item # FE258
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - Out Of Stock
Weight 2LBS
Community Q&A

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Browse 4 questions Browse 4 questions and 16 answers
Why did you choose this?
MoreFlavor Store
Ease of cleaning and a great price!!
Valued C on Aug 13, 2018
For a friend
Michael B on Aug 9, 2018
Ease of cleaning and a great price!!
Valued C on Aug 13, 2018
John O on Aug 10, 2018
For a friend
Michael B on Aug 9, 2018
A great design, for easy cleaning, and a good size for easy fermentation temperature control in a igloo cooler water bath
Dan Kuczmarski on Aug 9, 2018
Wide mouth and fits in my fermentation chamber.
Bernard W on Aug 8, 2018
Small batch brewing
Todd Z on Aug 8, 2018
To do split batches
Justin W Thomas on Aug 4, 2018
Wanted something small enough to use with Zymatic batches and the BrewJacket temperature controller. This should fill the bill.
Michael S on Jul 31, 2018
Lighter, less likely to break, easy to clean, cost less than glass
Steven McPeak on Jul 23, 2018
want to do split batches
Daniel B on Jun 12, 2018
Russell L on Jun 6, 2018
for making wine
J I on May 24, 2018
Want to make a small batch of wine
Charles Stahl on May 5, 2018
I'm currently making a lot of 3 to 3.5 gallon batches
Dustin P on Apr 13, 2018
John O on Aug 10, 2018
A great design, for easy cleaning, and a good size for easy fermentation temperature control in a igloo cooler water bath
Dan Kuczmarski on Aug 9, 2018
Any plans to offer this size with a spigot?
Tom Meskill on Jun 8, 2018
BEST ANSWER: We are always looking for new solutions and products. No confirmation if this will be manufactured with a spigot, but it's not out of the question. You could attempt drilling the plastic yourself.
Are the side walls thick? I purchased a 1 gallon version and am disappointed on how thin the side walls are compared to my 6 gallon Fermonsters.
Justin W Thomas on Jul 20, 2018
BEST ANSWER: Hello Justin - The side walls of FE258 and not quite as thick this as those on FE250.
On the larger versions, the line near the top where the sides begin to slope indicates there is one gallon of space left. Is that true for the 3-gallon version as well?
Douglas Frazer on Aug 17, 2018

4.7 / 5.0
3 Reviews
5 Stars
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1 Star
great fermenting containers
I like these Fermonsters because I can get my hand inside to clean it. Ordering and delivery from MoreBeer were quick and easy. I have a couple 5-gal Fermonsters that I used to make hard cider. This time I bought a couple 3-gal (and a 1-gal one) to make mead. The only down side, if you want to call it that, is it takes a lot of honey to make a 3-gal batch of mead. But my bees have been busy, the yeast is now busy in the Fermonsters, and soon I will be busy sipping the results.
August 6, 2018
3 weeks ago
I do like these carboys
This is a great size for doing batches of wine and mead. The wide mouth makes dealing with fruit in bags easy. Using all the different size Fermonster carboys are great way to brew and make wine. Lighter, safer, easy to clean and cost less than glass. The lids are interchangeable between carboy sizes too.
August 5, 2018
3 weeks ago
Light weight and easy to clean need I say more!!!
Dry hopped peach wine!
Dry hopped peach wine!
July 12, 2018
1 month ago