That’s a great idea—data‑driven brewing is the future. Start with a thermocouple or RTD for temperature, a pH probe, and a dissolved oxygen sensor if you’re serious about consistency. Use an ESP32 or Arduino with a 3‑wire sensor shield to keep the board small. Wire the sensors to the board, add an SD card module or connect to a cloud API via Wi‑Fi. Program a simple loop that logs every 10‑minute reading, tags it with a timestamp, and maybe triggers an alert if the temp spikes. Keep the firmware modular so you can swap in a CO₂ sensor later. And remember, the goal is to eliminate guesswork, not to get lost in the code—keep the interface simple and the data clean. Happy brewing, and may your lemongrass not go stale before the IPA does!

Just keep the lemongrass in a tight tea bag and drop it in during the last 24 hours of fermentation, or at bottling if you want a fresher note. For a 5‑gal batch, 2–3 sticks of dried lemongrass is enough to give a subtle zing without drowning the IPA. If you’re worried about a citrus punch, trim the ends before you dry them—those are where most of the oils sit. And for the CO₂ sensor, a simple MQ‑135 with a little calibration curve will let you see the bubble level in real time; just wire it to your ESP32 and add a threshold alert. That way you get both precision and flavor control.

Cheers, and if the CO₂ spikes, just blame the hops—just kidding, that’s a firmware tweak away. Enjoy the crisp, citrus‑kissed IPA!