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A fermenter should be easy to fill, sample, empty and clean. The five below cover the main materials, PET plastic, glass and stainless steel, and go from a simple wide-mouth carboy to steel fermenters with racking arms and pressure capability. For a deeper look, Little Big Mouth Bubbler Glass Fermenter Compared: 8 Options for Homebrewers covers this in detail.
Every specification on this page comes from the manufacturer’s own product page, checked on 26 October 2026. We have not used these products ourselves, so the picks are based on published specifications only.
For the pros and cons of each material, read choosing fermentation vessels, and see fermentation airlocks and controlling fermentation temperature.
How we chose these
- Material and capacity stated by the maker.
- Cleaning access described: wide mouth, removable lid or bottom valve.
- Limits published: temperature limits, pressure rating or handling cautions.
- A range from first batch to advanced brewing.
Comparison table
| Fermenter | Material | Capacity | Opening / ports | Pressure | Maker’s limits or cautions |
|---|---|---|---|---|---|
| Fermonster 6 gal | Clear BPA-free PET | 6 gal (5 and 6 gal marks) | 4 in wide mouth; lid with #10 stopper hole | No | No liquids hotter than 127 °F (53 °C); not below 35 °F (2 °C) |
| Big Mouth Bubbler EVO 2 | Hand-formed thick glass | 5 gal (gallon marks) | Wide mouth for pouring wort and adding flavorings | No | Handle with care; avoid sudden temperature changes; harness recommended |
| FermZilla All Rounder 30L kit | PET | 30 L | Threaded Easy-Grip lid ring; gas and liquid carbonation caps | Yes, with included 0 to 15 psi BlowTie spunding valve | Read KegLand’s instructions before pressurizing |
| Spike Flex | 304 stainless, 1.2 mm (18 ga) | 7 gal total; for 2.5 to 6 gal batches | 4 in TC top port; 1.5 in TC racking port with rotatable arm; 1.5 in TC secondary port | 2 psi working pressure | Spike sells 20+ accessories, up to a 15 psi brite tank setup |
| Reactor conical | 304 stainless | 8.5 gal | Wide lid with clamps; bottom dump valve; racking arm | Not stated | Not stated in description |
Pressure ratings are the makers’. Only use a fermenter under pressure if the maker says it is designed for it, and follow its instructions.
1. Fermonster 6 Gallon Fermenter: for a first fermenter
The Fermonster is a clear, food-grade PET carboy with a 4-inch wide mouth for filling and cleaning, graduated marks at 5 and 6 gallons and a one-piece lid with an O-ring and a #10 stopper hole for an airlock. The current version has 5% thicker walls, which the description says improves oxygen resistance and durability.
- Made in Canada from virgin food-grade materials; suitable for beer, wine, cider and kombucha (product description).
Pros: light and clear; wide mouth for cleaning; lid with airlock hole included.
Cons: temperature limits: no hot wort above 127 °F.
2. Big Mouth Bubbler EVO 2 (5 gal glass): for glass with a wide mouth
Northern Brewer’s Big Mouth Bubbler EVO 2 is a thick, hand-formed glass fermenter with a ground, flat neck top for an airtight seal and a mouth wide enough to pour cooled wort straight in from the kettle. Gallon marks show the volume, and the taller, narrower body is meant to leave less liquid behind when you transfer.
- Northern Brewer warns that extreme temperature changes or sudden contact with hard surfaces may crack the glass and strongly recommends its carrying harness.
- A 6.5 gallon version is also sold.
Pros: thick glass that Northern Brewer says eliminates oxygen permeation; wide mouth.
Cons: heavy and breakable; needs careful handling. For a deeper look, 10 Best 6 Gallon Stainless Steel Fermenter Options for Homebrewers (2026) covers this in detail.
3. KegLand FermZilla All Rounder 30L Starter Kit: for pressure fermenting in a light PET vessel
FermZilla is a PET fermenter built to hold pressure, so you can ferment under pressure and transfer to a keg using CO2 to reduce oxygen pickup. This starter kit includes gas-in and liquid-out carbonation caps, a weighted stainless float with a silicone dip tube and mesh filter, a hex base and a BlowTie spunding valve with gauge, 0 to 15 psi.
- KegLand recommends a CO2 supply for transfers, sold separately.
- Sold on KegLand’s Australian store; check availability where you live.
Pros: pressure fermenting and closed transfers in a light vessel; complete kit.
Cons: needs CO2 and kegging gear to get the full benefit.
4. Spike Flex: for a stainless fermenter you can upgrade
Spike’s Flex is a polished 304 stainless fermenter with sanitary welded ports, a rotatable racking arm and etched volume marks. It starts as a simple bucket fermenter with an airlock and can be upgraded with Spike’s accessories. At its 2 psi working pressure it can push beer into a keg or bottling bucket.
- Size: 15 in wide by 21 in tall to the top of the airlock (Spike).
Pros: stainless and light-proof; racking arm; upgrade path.
Cons: more parts to clean than a carboy; full pressure use needs accessories. If you want more background, see 9 Best Wide Mouth Glass Fermenters for Homebrewing (2026).
5. Northern Brewer Reactor Stainless Steel Conical: for dumping yeast without moving the beer
The Reactor’s conical bottom lets yeast and trub settle so the clearest beer stays above, and its bottom dump valve drains sediment or cleaning solution without tipping the fermenter. An adjustable racking arm lets you sample during fermentation and transfer for bottling or kegging. The 8.5-gallon capacity leaves headspace for vigorous fermentations. Worth reading next: 7 Best Kombucha Homebrew Kit Compareds: 7 Picks for Beginners (2026).
- Includes a lid with removable silicone gasket, size 5 drilled stopper, racking arm assembly, bottom valve, spare gaskets and rubber feet (Northern Brewer).
Pros: conical shape and dump valve; large headspace; light-proof steel.
Cons: largest footprint here; overkill for occasional brewers.
Which one fits you
| You | Look at | Why |
|---|---|---|
| Brew your first batches | Fermonster 6 gal | Light, clear, wide mouth |
| Prefer glass | Big Mouth Bubbler EVO 2 | Thick glass with a wide mouth |
| Want to keg with less oxygen | FermZilla All Rounder or Spike Flex | Pressure transfer capability |
| Want to dump yeast and trub | Reactor conical | Bottom dump valve |
Practical tips
- Cool wort before it goes into a plastic fermenter; the Fermonster’s limit is 127 °F (53 °C).
- See our fermentation monitoring guide for checking progress once the fermenter is sealed.
Sources
Specifications from each manufacturer’s product page, checked 26 October 2026: Fermonster 6 Gallon Fermenter, Big Mouth Bubbler EVO 2 (5 gal glass), KegLand FermZilla All Rounder 30L Starter Kit, Spike Flex, Northern Brewer Reactor Stainless Steel Conical. Makers can change specifications; check the product page before you buy.
About Graham Fisher
Graham Fisher is part of our editorial team and reviews and edits our home brewing guides, checking product details against manufacturer specifications and owner feedback.
