Fermentation is a dance between control and surrender. We create the conditions, add the culture, and then step back to let an invisible world of microbes work its magic. But any fermenter knows that the environment is everything. The wild sourdough that thrives in a cool, humid kitchen might struggle in a warm, dry one. The perfect kimchi requires a consistent chill. A home-brewed beer like a lager demands a precise, unwavering cold fermentation, while an ale needs a steady warmth. The mash for a future distillation, perhaps using surplus lemons or plums from your own garden, needs to be kept at an optimal temperature to ensure a clean ferment, free of off-flavours. Even a simple Hard Lemon brew can turn if the temperature swings too wildly.
Traditionally, we found these environments in nature—in root cellars, cool pantries, or basements. In our modern homes, creating that consistency is a challenge. This project is about reclaiming that control, not to dominate the process, but to become a better collaborator with our microbial partners.
We are building a DIY Wireless Fermentation Controller—an open-source project to create a small, sentient chamber where you can precisely manage temperature, humidity, and airflow. It’s about using modern technology to replicate the ancient wisdom of the cellar.
A Dialogue with Your Ferment
This isn’t an industrial black box. It’s an open, adaptable system designed to empower the home artisan. The controller acts as the brain for a simple chamber (like a modified old fridge or an insulated box), turning it into a responsive micro-environment.
The core features include:
- Temperature Control: Using a heating pad and the chamber’s cooling system (or a thermoelectric cooler), it can hold a precise temperature. This is critical for home-brewing beer, allowing you to step-mash or maintain the steady 10°C for a clean lager ferment. It’s just as crucial for a distiller’s mash, where a consistent temperature profile ensures the yeast produces the desired esters without stress. For simpler projects like a Hard Lemon from garden fruit or making tempeh, it prevents spoilage by keeping the environment in the perfect range.
- Humidity Management: A sensor-driven humidifier or dehumidifier maintains the ideal moisture level, crucial for processes like making salami or aging cheese.
- Airflow Regulation: A small, managed fan provides gentle air exchange, preventing unwanted mould and ensuring an even environment.
- Wireless Connectivity: This is where it comes alive. Using WiFi, the controller integrates seamlessly with platforms like Home Assistant, allowing you to monitor your ferment, adjust settings, and receive alerts from anywhere. For more remote or off-grid applications, we are building in LoRaWAN capability, allowing the chamber to connect to community-owned networks like The Things Network.
The Components of a Living Chamber
This project is designed to be built with accessible, open-source components. While we will provide detailed build logs and code in future posts, here is the conceptual blueprint:
- The Chamber: An old bar fridge is perfect, as it’s insulated and has a cooling system. An insulated cooler or custom-built box also works wonderfully.
- The Brains: A WiFi-enabled microcontroller like an ESP32 is the ideal core, powerful enough to manage the sensors and relays while communicating wirelessly.
- The Senses: A reliable sensor like the BME280 or DHT22 provides the brain with real-time temperature and humidity data.
- The Climate Toolkit:
- Heating: A simple reptile heating mat or a small ceramic heater.
- Cooling: The fridge’s own compressor or a Peltier (thermoelectric) cooler for smaller builds.
- Humidity: A small USB-powered ultrasonic humidifier.
- Airflow: A standard 12V DC computer fan.
- The Power: A relay board safely switches the higher-voltage components (like the fridge and heater) based on commands from the microcontroller.
Reconnecting the Circles: Why This Matters
This project is a perfect microcosm of the SEIN philosophy:
- Sense: We are using sensors to listen to the needs of a living system.
- Grow/Ferment: We are creating the ideal conditions for life to thrive, often using produce from our own gardens to come full circle.
- Openness: By making the project open-source and controllable via platforms like Home Assistant, we empower a community of makers to adapt, improve, and share. The LoRaWAN integration is a step towards a truly decentralised, community-owned infrastructure, free from corporate control.
Join Us in the Making
This is an active, evolving project. We are currently refining the hardware design and developing the open-source firmware. The goal is to create a simple, reliable, and powerful tool that any passionate fermenter can build and use.
We invite you to join the conversation. We’re looking for feedback and collaborators—from home brewers and small-scale distillers to artisan food producers and electronics hobbyists.
This is more than a controller. It’s a tool for a deeper conversation with the microbial world. It’s a way to use technology to get closer to ancient crafts, and to make, share, and enjoy the fruits of our collaboration.
Detailed schematics, code, and build guides will be shared here as the project develops.