Grainfather G30 and G40 Review

G30 or G40

The only question that matters is batch size

These are the same system at two sizes, and the decision is simpler than the marketing makes it. Control, pump and chiller philosophy are shared. What differs is vessel volume and therefore footprint.

• G30 -- 30 L vessel, around 23 L finished. A standard 5 to 6 gallon batch, comfortably. Fits a kitchen counter and can be lifted by one determined person. No headroom for a big barleywine and no path to 10 gallon batches.
• G40 -- 40 L vessel, around 30 L finished. A full 8 gallon batch, or a 6 gallon high-gravity one with room to spare. Heavy enough that where you install it is where it lives.

The usual advice applies: buy one size up from what you brew today, because batch sizes drift upward and vessels do not. If you are genuinely space-constrained, the G30 is the right answer and the constraint is real.

The premium

Three things it buys, and whether you need them

Variable-speed recirculation. The only system in the mid tier that lets you dial pump speed rather than run flat out. This matters if your crush is tight: too much flow through a finely crushed bed compacts it and stalls the mash, and being able to throttle back is the fix. If you mill to a conservative gap, you will rarely use it. See grain mill gap settings.

App quality. Community consensus is clear that the Grainfather app is the best documented and most reliable in the category. That is a low bar the category frequently fails, and it is worth something on a four-hour brew day.

Official support. Documentation exists, parts exist, and there is a company to ask. The flip side is that the ecosystem is proprietary -- when you want a fitting Grainfather does not sell, the answer is often that you cannot have it.

Limitations

Price, weight and the walled garden

The price premium over a BrewZilla is real and not small. For that money you get the software and the pump control, and you do not get more beer or better beer. If neither of those two things is something you will use, the premium buys nothing you need -- which is the argument in Grainfather vs BrewZilla.

The G40’s weight is worth a thought before purchase rather than after. A full 40 L vessel is heavy, and the system is not designed to be moved between a cupboard and a counter each brew day. Plan a permanent home for it.

Verdict

Where these placed

The G40 is our best automated pick in best all-grain systems and our best for 10 gallon batches in best electric brewing systems; the G30 is the compact pick in the same roundup. If you have not compared it against the Foundry, see Anvil Foundry vs Grainfather, or all three in the three-way comparison.