Adjustments for mashing - legacy software

This is my first post on the forum, so please bear with me :smiley:

I run legacy Brewpi on 3 arduino uno’s : 2 freezers and a mash tun. The freezers work perfectly to manage fermentation and I must say that Brewpi is in my humble opinion absolutely brilliant.

I’m aware that the legacy software was not designed to manage a mash profile, but rather to manage ambient temp in order to achieve a desired beer temp. Having said that I’ve been getting away with using the fridge constant mode for my mash tun, although I get an overshoot of a few degrees during mashing.

My question is whether I can adjust the heating overshoot estimator in advanced settings to try and reduce the overshoot. Obviously PID settings are irrelevant here. I have no mathematical brain, so have no idea how to approach it. If I reduce the overshoot factor, will it improve overshoot or make it worse? Also, is there any point to that, as the algorithm adjusts it automatically anyway? Should I just run the mash tun for a few hours and allow the software to improve its overshoot estimation?


The arduino firmware really isn’t written with mashing in mind. It doesn’t use PWM like the Spark firmware. It also has hard coded minimum heating and cooling times, which will get in the way of proper mash temp control. Those minimum times are chosen with a fridge setup in mind.

At least you’d need to remove those hardcoded minimum times by re-compiling the code. Even then, it won’t work nearly as well as the new firmware with PWM.

I have mashed with modified Arduino code before the PWM firmware was ready, but it wasn’t ideal.

I won’t be able to assist with modifying the firmware, because the Arduino version is end-of-life and my time is better spent improving the current version of the software.

Thanks Elco. I think it may be time to knuckle down and buy the Spark. I guess I’d leave the Arduinos to control the freezers and dedicate the Spark to my mash set-up. If so, will one wall mounted sensor suffice (in place of the thermowell that I currently use) or would I need two sensors? Also, would I be able to use the Spark standalone or in conjuction with my Rasp Pi?

With the raspberry pi. You can use a single pi for multiple servers with docker.

If you already have a thermowell, you can use the simple sensor we sell. It fits most thermowells.
Do you have a HERMS, RIMS or BIAB?
In case of a HERMS, you should also put a sensor in the HLT.