Grainfather STC-1000 upgrade

The Grainfather STC-1000 upgrade: On controllers and software

UPDATE: When I wrote this, the Grainfather Connect didn’t exist. So now you can buy something off the shelf that makes the Grainfather do everything the STC-1000 upgrade does and far more. It’s all controlled via Bluetooth and allows you to brew from your couch.

I haven’t bothered to upgrade my system to the new controller as I’m very happy with the STC-1000 solution, and for some reason having all the Bluetooth awesomeness feels a little like cheating…

The Grainfather is an awesome brewing machine, no doubt about it. It does suffer a little by comparison to the big German heavyweight, the Speidel Braumeister. The Braumeister has a clever little computer onboard that controls the mash, turns the pump on and off, steps the mash through different temperatures and warns you when things need to happen. It’s a classy machine, and the Grainfather is often compared to it and seems to come up a little short.

stc200iMake (the company behind the Grainfather) kept the Grainfather simple and it uses off the shelf parts. This makes it very easy to repair should something go wrong. The ‘brain’ of the Grainfather is a little temperature controller called an STC-200. They’re pretty common and you can find them on ebay pretty easily. It does the trick. It holds the temperature at a set point by switching the element on when it’s below the set point and off when it goes above. It’ll hold the temperature to within a degree or two. If you want the mash to be at a different temperature (like for step-mashing) then you have to change it yourself.

There’s a very popular temperature controller amongst the home brew community called the STC-1000. It’s a cult item and it runs fermentation fridges and kegerators right across the globe. Some very clever software engineers (mainly a guy called Mats Staffansson from Sweden) discovered there were versions of the STC-1000 that were able to be flashed with new firmware. New software was written from scratch and a system of uploading it to the STC was devised using an Arduino. This allowed the little STC-1000 to do things you never thought possible, like slowly ramping a temperature up over several days before crashing it back down to near zero, all without touching the controller. Mats Staffansson turned a $30 controller into something equal to products that cost a couple of hundred. The software was dubbed the STC-1000p.

Once the fermentation software was complete, other projects using a modified version of the STC-1000p were dreamed up, including software that turns the STC-1000 into a controller for a single vessel brew system. The Grainfather is a single vessel brew system…

The Grainfather STC-1000 upgrade: Automated step-mashing anyone?

So, I gave my Grainfather an STC-1000 upgrade. Purchasing an appropriate STC unit can be a bit of a lottery. There are loads of them for sale on eBay and AliExpress, but not all of them can be upgraded. I bought one for the Grainfather, only to find when it arrived that it was the wrong one. Then I saw on the STC-1000p project page the following:

STC-1000+ is only compatible with the A400_P version of the STC-1000. This is manufactured (and also sold) by HongKong U-control electric CO Ltd. STC-1000’s can be purchased directly from them through their webshop on Aliexpress.

Bingo! I ordered one from them direct. Yes, it’s a little more expensive than what you can find on eBay, but it’s a guaranteed upgradable one. It arrived, and it was exactly right and ready to be upgraded.

The single vessel software is here. It uploaded perfectly.

Grainfather stc-1000Installing into the Grainfather was a piece of cake. There are three pairs of wires, and they need to be swapped out like for like. The mains goes to the mains, the element to the heating relay and the temperature probe to the temperature probe. The wires can simply be unscrewed from the STC-200 and screwed into the STC-1000. The only real difference is that the mains and heating relay are on opposite sides to each other, so you have to slightly re-route the cables. It’s really not a big issue. The temperature probe is the same, so just connect the old probe straight into the new brain. I tested the probe against a thermometer I trust and it was within 0.2°C. Bang on.

Once everything was reconnected I put 10 litres of water in there and put it through its paces. Programming a mash schedule isn’t the easiest thing in the world (hey, they did the best they could under the limitations of the machine—the software is a work of genius!). I programmed a simple step program: 50°C 60°C 70°C, each step for 5 mins then boil for 15 mins with two hop addition warnings. No grain this time, just water. The machine calmly went through the entire program without a hitch. The pump remains a manual switch, but I’m OK with that.

I have just doubled the awesomeness of my Grainfather. It’s even more like a Braumeister now, and it cost $30 to upgrade. Not bad. Not bad at all!

I particularly like that there are no permanent changes. No holes were drilled, no wires cut and no plastic trimmed. You could put the STC-200 back in in about 10 minutes and the GF would be back to it’s old, slightly stupid self. If you own a Grainfather, and aren’t the type to worry about voiding your warranty then this is worth a go!

If you want a hand with it then contact me: