The Best Plastic Conical Fermenters

Why plastic is a serious choice

Three real advantages over stainless

Plastic conicals are sometimes treated as the compromise option. They are not -- they do three things welded stainless cannot, and for many brewers those three things matter more than longevity.

• You can see what is happening. Watching krausen rise and fall, seeing exactly when the trub layer has dropped, and being able to confirm a stuck fermentation visually rather than by inference. Opaque stainless gives you none of that, and for a brewer still learning fermentation, visibility is genuinely instructive.
• Weight. A full PET vessel can be lifted by one person. A full stainless conical generally cannot, which affects where you can put it and how you clean it.
• Price per capability. A FermZilla Tri-Conical with its pressure kit does closed transfer and yeast harvesting for a fraction of what a rated stainless vessel costs. That means pressure fermentation is accessible to brewers for whom a Spike CF5 is not.

The real limitation

PET scratches, and scratches are the whole problem

The honest downside is not that plastic is flimsy -- these vessels are robust and hold pressure reliably. It is that PET scratches, and a scratched interior surface is a sanitation liability: soil sits in the scratch where sanitizer contact time cannot reach it, and an infection that survives one batch can survive the next.

That makes cleaning technique the deciding factor in how long the vessel lasts:

• Never use an abrasive. No scouring pads, no scrubbing brushes with stiff bristles, no bar keeper’s friend. A soft cloth or a soft sponge only.
• Soak, do not scrub. A non-caustic alkaline wash at warm temperature for twenty to thirty minutes removes soil without mechanical effort. Let the chemistry do the work.
• Rinse immediately after transfer. Dried krausen ring is far harder to remove than fresh, and hard removal is what causes scratches.
• Retire it when it stops looking clear. A hazy, finely scratched interior is a vessel at the end of its life. Plan on several years, not decades.

Cone or cylinder

Whether you actually need the cone

The FermZilla range offers both, and the decision is worth thinking about rather than defaulting to the cone. A cone gives you trub separation and bottom yeast harvesting. A cylinder is shorter, cheaper, easier to clean, and fits chambers the coned version will not.

If you harvest yeast, take the cone. If you do not -- and most homebrewers do not -- the All Rounder does pressure fermentation and closed transfer just as well, in a package that is easier to live with. That comparison in full: FermZilla Conical vs All Rounder.