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The FermZilla All Rounder and FermZilla Conical are Kegland’s two pressure-capable fermenters targeting homebrewers who want closed-transfer and pressure fermentation capability at accessible prices. I’ve brewed with both and the pressure rating comparison is one of the most practical distinctions between them, alongside some significant ergonomic differences that aren’t obvious from the product specs alone.
FermZilla All Rounder vs. Conical: design and pressure specs
FermZilla All Rounder: A spherical/rounded PET plastic fermenter with a wide-mouth lid, available in 30L and 60L versions. The rounded body design distributes pressure more evenly than a cylindrical vessel, contributing to its pressure rating. Pressure rating: 35 PSI (2.4 bar) working pressure, tested to higher burst pressures. The 35 PSI rating is sufficient for: natural carbonation (typical serving pressure for most beer styles is 10–14 PSI), pressure fermentation at lager temperatures (15–20 PSI), and closed transfers where CO2 pressure pushes beer from fermenter to keg. Tri-clamp fittings standard on the collection ball at the bottom. Spunding valve port included for pressure fermentation setup. The All Rounder’s wide-mouth lid (approximately 10cm opening) allows cleaning with a brush but does not allow hands-inside cleaning access. The rounded PET body is clear, allowing visual monitoring of fermentation activity and yeast layer. Price: approximately $80–120 USD for the 30L version. FermZilla Conical: A cylindrical stainless steel conical fermenter (true cone-bottom design) with collection vessel at the apex for yeast and trub harvesting. Available in 35L, 55L, and 110L versions. Pressure rating: 15 PSI (1.0 bar) working pressure, significantly lower than the All Rounder’s 35 PSI. The 15 PSI rating supports pressure fermentation at standard pressure lager protocols (10–15 PSI) but provides no safety headroom above the working pressure. The conical bottom provides the primary advantage over the All Rounder: clean yeast separation. The collection vessel at the cone apex allows periodic dumping of settled trub and spent yeast without disturbing the beer layer, enabling yeast harvesting and extended conditioning in the same vessel. Tri-clamp connections throughout for hose attachment and transfer. Price: approximately $200–350 USD depending on size, significantly more than the All Rounder. The pressure rating gap matters: The All Rounder’s 35 PSI rating versus the Conical’s 15 PSI is a meaningful practical difference. At 15 PSI working pressure, the Conical’s pressure fermentation headroom is thin, any pressure spike from vigorous fermentation or accidental over-pressurization approaches the safety margin. The All Rounder’s 35 PSI provides comfortable headroom for the 15–20 PSI pressure fermentation protocol, natural carbonation, and force carbonation in the vessel. For pressure fermentation specifically, the All Rounder is the safer and more capable vessel despite being significantly cheaper.
Which fermenter for which use case
Choose FermZilla All Rounder when: Pressure fermentation is a primary use case, the 35 PSI rating provides comfortable working pressure with safety headroom. Budget is a consideration, the All Rounder is 40–60% cheaper than the Conical for equivalent volume. You want natural carbonation in the fermenter (transferring from vessel to keg without opening, the All Rounder handles the full carbonation pressure). You don’t need conical yeast separation (batch harvesting by draining the yeast slurry from the collection ball is less clean than a true cone separation but workable). Choose FermZilla Conical when: Yeast harvesting and reuse is a priority, the cone-bottom design separates yeast cleanly for collection and repitching. You’re doing longer conditioning periods (4+ weeks) where the ability to dump trub without disturbing the beer matters. You want a more professional fermenter aesthetic and all-stainless construction. You brew lower-pressure styles where the 15 PSI limit is not a constraint. Combined use case: Some brewers use the All Rounder for pressure fermentation and the Conical for conditioning and yeast management, leveraging each vessel’s strongest capability.
Common Questions
Is it safe to naturally carbonate beer in a plastic PET fermenter like the All Rounder?
Yes, natural carbonation in PET pressure vessels like the FermZilla All Rounder is safe when the vessel is used within its rated pressure and the beer is carbonated to normal serving carbonation levels. The safety context: natural carbonation in beer typically reaches 2.5–3.0 volumes of CO2, which corresponds to approximately 10–14 PSI at 4°C serving temperature. This is well within the All Rounder’s 35 PSI rating. PET (polyethylene terephthalate) is a food-safe plastic used for carbonated beverage bottles, 2-liter soda bottles and carbonated water bottles are PET at similar or higher pressure ratings. The material is proven for carbonated beverage storage at normal serving pressures. The precautions for safe natural carbonation in the All Rounder: confirm fermentation is complete before sealing for natural carbonation (an incompletely fermented beer will over-carbonate and exceed safe pressure); use a calibrated priming sugar calculation (many homebrewers use priming calculators, the standard is 5–6g of table sugar per liter for 2.5 volumes); use a spunding valve set to release pressure above 14–15 PSI as a safety relief during the carbonation period; store at fermentation temperature (18–20°C) during active carbonation, then cold crash to serving temperature once carbonation is complete. The FermZilla All Rounder specifically includes a spunding valve port for exactly this natural carbonation use case. Kegland rates the vessel for this use, and the homebrewing community has used it for natural carbonation extensively without safety incidents when operating within the rated pressure range.
