A common question that people ask on HomeBrewTalk is how the various BrewPi offshoots differ. At the moment, there are four major variants of BrewPi firmware in common use:
|OG Legacy BrewPi||BrewPi-Remix||BrewPi-ESP32*||BrewPiLess|
|Microcontroller||Arduino Uno||Arduino Uno||ESP32*||ESP8266|
|Screen Support||Parallel LCD2004||I2C LCD2004||TFT||??|
|Free & Open Source||✔️||✔️||✔️||✔️|
|Fridge/Beer Constant Mode||✔️||✔️||✔️||✔️|
|Fridge Profile Mode||✔️||✔️||✔️||✔️|
|"Server Free" Mode||P||✔️|
|"Server Supported" Mode||✔️||✔️||✔️|
|Supports Pressure Control||✔️|
|Supports Kasa WiFi Relays||✔️|
|Tilt Temp Sensor Support||✔️|
* - BrewPi-ESP supports the ESP8266, ESP32-S2, and ESP32 chips. The ESP32 variant is shown above.
The original BrewPi firmware was designed for the Arduino Uno which was one of the earlier, "hacker-friendly" microcontrollers. Devices built using this firmware have been in continuous use for years at a time proving their robustness.
The BrewPi-ESP and BrewPiLess projects use chips from Espressif that are (often) cheaper, have additional memory capacity, WiFi radios, Bluetooth radios, and other interesting features. The more powerful hardware has meant new features could be added like Kasa WiFi Relay and HTTP Server support.
The original BrewPi firmware supported the use of a 4 row, 20 character LCD2004 screen hooked up with a parallel (16-pin) interface. That's a lot of soldering/wires, so BrewPi-Remix added I2C LCD2004 support bringing this down to 4 pins. BrewPi-ESP supports both I2C LCD2004 screens as well as 320x240 TFTs, bringing substantially more screen real estate.
Free and Open Source
All of these options are based on the original BrewPi Firmware, and all are licensed under GPL. They are all freely available for download/use, and can be redistributed under the terms of the GPL license
Temperature Control Modes
All BrewPi derivatives work in "fridge constant" (simple thermostat) mode, "beer constant" mode (where a PID loop is used to tightly control the temperature of your fermenting beer, often to within 0.2 F), and "beer profile" mode (where a series of setpoints and temperature ramps can be defined, to automatically perform a diacetyl rest, for example).
Beer Profile mode works in conjunction with the web service – for original BrewPi, BrewPi-Remix, and BrewPi-ESP this means that the profile will "hold" at the then-current setpoint if connection to the web service is lost. In the case of BrewPiLess, the profile is executed entirely on the device.
BrewPi firmware was intended for indirect, compressor-based temperature control, where the thing being heated/cooled (the air in a fridge/chamber) then helped heat/cool the beer being fermented. Certain features provided by BrewPi are not as relevant in a Glycol setup, such as the need for a second probe (beer vs. fridge) or the need for compressor protection.
BrewPi-Remix has a "glycol mode" available that reduces the delays, zeroes a number of the PID values, and uses "fridge constant" mode to better control beer temperature.
BrewPi-ESP allows for configurable compressor protection, allowing much faster cycling in a glycol system than would otherwise be allowed. BrewPiLess also adds support for "fridge profiles" which are similar to Beer Profiles, but do not integrate the beer PID loop.
"Server Free" vs. "Server Supported/Required"
BrewPi was originally designed for (and named after!) a setup where the controller was permanently connected to a Raspberry Pi running software to support it. This software logged temperatures, managed temperature profiles, and configured the hardware controller for use.
Modern versions of this "server" component - Fermentrack and BrewPi-Remix - are compatible with the original BrewPi hardware, BrewPi-Remix Arduino controllers, and BrewPi-ESP controllers.
The latest version of BrewPi-ESP integrates a new, on-chip webserver which allows for quick configuration and temperature control without going through Fermentrack/BrewPi-Remix while retaining the ability to integrate with Fermentrack/BrewPi-Remix for extended logging/control features. BrewPiLess does not require - and does not support - the use of a server-hosted component.
Kasa WiFi Relays
BrewPi controllers use hard-wired relays to control power to heating/cooling in order to control temperature.
BrewPi-ESP allows for the optional use of Kasa WiFi Relays in place of hard-wired relays for controlling power to heating/cooling. This can reduce the effort required to build a controller, and potentially eliminate the need for soldering/crimping/wiring to mains power.
Tilt Hydrometer Temperature Sensor Support
BrewPi controllers use hard-wired DS18b20 temperature sensors to detect the temperature of both the fridge/chamber and the beer.
BrewPi-ESP allows for a Tilt Pro Hydrometer to optionally serve as a beer temperature sensor instead of a DS18b20. This can be used at the same time as any other Tilt logging solution such as TiltBridge or Tilt Pi, and can potentially eliminate the need for soldering temperature sensors to the controller.
The original BrewPi required a permanent, hard-wired connection from the controller back to the server. BrewPi-ESP allows the optional use of WiFi to connect from the temperature controller back to Fermentrack or BrewPi-Remix. BrewPiLess requires the use of WiFi for devices to connect to it.
Fermentrack is an enhanced platform for fermentation monitoring and control. While BrewPi-www provides a basic interface for temperature regulation during fermentation, Fermentrack offers a more user-friendly interface, supports multiple controllers including Arduino and ESP8266-based devices, and boasts better integration with other tools. Fermentrack supports original, Arduino-based BrewPi devices, devices using the BrewPi-Remix Arduino firmware, and was made specifically to support BrewPi-ESP.
In the dynamic world of homebrewing, technological advancements have led to a range of BrewPi derivatives, each offering its own set of unique features. From the original BrewPi firmware designed for the Arduino Uno to the more recent BrewPi-ESP and BrewPiLess, there's an evident progression towards increased functionality, versatility, and user-friendliness. The integration of advanced features like Kasa WiFi Relays, Tilt Hydrometer Temperature Sensor support, and enhanced screen support have made modern systems more intuitive.
The choice between them boils down to individual brewing needs, whether you desire a traditional setup or one augmented with the latest tech features. BrewPi has undeniably set a firm foundation, and its offshoots have carried the torch, pushing the boundaries of what's possible in fermentation monitoring and control. Whether you're a beginner or a seasoned brewer, there's a BrewPi variant out there tailored to enhance your brewing journey.