The Best Brew Kettles

Sizing

Fifty percent larger than the batch

This is the decision people get wrong and cannot undo. A 5 gallon batch has a pre-boil volume around 7 gallons once you account for boil-off and grain absorption. Hot break foams up substantially in the first minutes of the boil. And the margin between a vigorous boil and a boilover is a couple of inches of freeboard.

So a 5 gallon batch wants a 10 gallon kettle. An 8 gallon kettle technically works and means watching the boil instead of running it, which sours a brew day quickly. At 10 gallon batches the equivalent figure is 15 gallons.

Buy one size above what you brew today, because batch sizes drift upward and kettles do not shrink. It is the cheapest insurance in this category.

Welded or stamped

A ten-year question, not a today question

Welded tri-clamp ferrules are permanent, crevice-free joints that take a standard gasket. When the gasket perishes you buy a gasket, from anyone, indefinitely. There is also nowhere for soil to hide in a continuous weld.

Stamped fittings are a hole with a bulkhead and an O-ring. Cheaper to manufacture, perfectly functional, and when one starts weeping your options narrow -- sometimes a new O-ring, sometimes the end of the kettle.

For most homebrewers this never becomes a problem, because most homebrewers do not keep one kettle for fifteen years. If you intend to, welded is the difference between maintaining equipment and replacing it -- the same argument as appliance versus rebuildable rig on the systems side.

Clad bases

Required for induction, useful on gas

A tri-clad base is a sandwich of stainless, aluminum and stainless. The aluminum core spreads heat laterally, which does two useful things:

• It makes the kettle work on induction. Induction hobs are an excellent indoor heat source -- fast, controllable, no combustion -- and a thin single-layer stainless kettle performs badly on one.
• It reduces scorching on gas. A propane burner concentrates heat in a ring, and without lateral conduction you get hot spots that scorch wort sugars onto the bottom.

If you are brewing on gas with a wide burner and have no induction plans, a plain base is adequate. Otherwise the clad base is worth the small premium. Heat source options in general: electric vs propane brewing.

Ports

What fittings you actually want

• A ball valve near the bottom. Essential. Draining by siphon or by lifting a full kettle is both unpleasant and dangerous.
• A thermometer port, useful for monitoring the boil and genuinely important if you mash in the kettle.
• A whirlpool return port, only if you pump. It lets you recirculate to settle trub into a cone in the center before transferring.
• A pickup tube or dip tube, which determines how much wort you leave behind. A tube reaching the lowest point of the kettle wastes less.

If you mash in the kettle rather than a separate vessel, you also need a false bottom sized to its internal diameter.