The Grainfather family has grown! Part two: The S40

Posted on 25th October 2021

Grainfather have announced two new additions to their family of all-in-one brewing system. We’ve covered the advanced new G40 – now we’ll have a look at the new S40.

The S40 – simple and straightforward

The “S” marks this system as the first of a new product line from Grainfather, focusing on simplicity of experience. Stripping out more complex features also reduces the cost, but while the S40 is a more affordable machine than the G series systems, it’s by no means a cheap imitation.

S40 front view

S40 vital statistics

Height 680 mm (27 inches)
Diameter 480 mm (19 inches)
Weight (empty) 18 kg (40 lb)
Minimum grain bill 5 kg (11 lb)
Maximum grain bill 10 kg (22 lb)
Minimum batch size 10 litres (3 US gal)
Maximum batch size 40 litres (11 US gal)
Maximum boil volume 46 litres (12 US gal)
Heating element 2300 watts
Pump 25 watts
Control unit Manual only

The S40 is a similar shape to other GF systems, but you’ll notice the tap at the bottom. This is a clue to a major difference in how you use the S40. Where other Grainfather systems sit on the floor and pump the finished wort out, the S40 is intended to sit on a bench or worktop and simply drains by gravity. This kind of pragmatism is present throughout the S40, keeping the price down by reducing complexity.

That’s not to say this is a lesser machine. The grain basket is a similar design to the one in the G40, with rolled edges on the plates (so no silicone seals to fit) and the new side perforations that do away with the centre overflow pipe needed on the G30. The basket sits on four legs to keep it clear of the element, hence the slightly higher minimum grain bill than the G40. This also means that, while the maximum boil size is 40 litres, in practice the maximum you can sparge to is about four litres less than this, as any more liquor starts to meet the grain basket. If you do want to reach that maximum boil size, we suggest draining the spent grain in a second vessel after sparging (e.g. a plastic bucket), then adding that liquor to the boil.

You also still get the benefit of recirculation mashing thanks to the powerful pump. We actually found we needed to throttle back the pump in our tests, so strong was the flow!

The element is switchable between 2.3kW – more than powerful enough to bring 40 litres to boil – and a lower 1kW setting better suited to maintaining mash temperatures. You can dial in your desired temperature via the manual control unit on the front of the system, and this will activate and deactivate the element to sustain that temperature (the G series systems are more complex, scaling power to the element instead). Make sure you select the appropriate element power with the switch on the side when moving from initial heating to mashing and again to boiling.

Unlike the G series systems, there’s no built-in filter on the S40. We suggest adding a bazooka filter inside the tap to avoid potential blockages; another approach would be to use a hop spider. Or you could simply place hop additions in a fabric bag. The S40 is a keep-it-simple system!

Flaked Oats

Our favourite feature

The lack of automation here is kinda the point. This is a more hands-on system that does what you tell it to, when you tell it. You don’t need the Grainfather app – though it is still very useful for working out water volumes etc. – nor a wireless / Bluetooth device. You get the high-quality hardware of other Grainfather systems – a proper recirculating mashing system, a really powerful pump, the carefully designed grain basket, robust stainless steel construction – without the complexity that the G series’ more advanced features bring.

Should I buy one?

If you’re a BIAB brewer looking for an upgrade with the same workflow you’re used to – the S40 is for you. If you’re a three-vessel brewer tempted by an all-in-one system, but the idea of running your brewday through an app leaves you cold, the S40 is an ideal choice. Likewise, if you’re brand new to brewing and want to get hands-on with the processes, the S40 is the system for you. The minimalist design approach makes the system budget-friendly, but this is no cheap knockoff – the features here are well designed, robustly built, and fully supported by a two-year warranty.

Browse the full range of Grainfather brewing systems


If you’d like to learn more about the S40, check out our videos covering everything from unboxing and assembly through to real brews – and tests where we find out just how well the official specifications hold up.

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