"A watched pot never boils"

So stop watching.
PotWatch does it for you.

A clip-on timer that senses the exact moment your water truly boils — and only then starts the countdown. Perfect eggs benedict, soft or hard, every single time. And the best part: you build it yourself, from about EUR 25 of common parts.

PotWatch device with OLED display showing the preset menu
The problem

Every kitchen timer starts too early.

"Three minutes for a soft-boiled egg" does not mean three minutes from when you pressed the button. It means three minutes of boiling. So you stand at the stove watching for bubbles, guess the moment, and accept that breakfast is a coin flip.

PotWatch takes that judgement away from you. It hangs on the rim of the pot with a stainless steel probe in the water, waits for a genuine, confirmed boil, and only then starts counting. When the food is ready it shouts until you answer.

You can walk away. That is the entire point.

97.6°C
where water actually boils in a typical kitchen — not 100
consecutive confirmations before the countdown starts
2
buttons. No app, no account, no cloud
~€25
of common parts, and an evening to build it
Why it is worth building

Small clip. Serious engineering.

🎯

Repeatable results

Because timing starts from the real boil rather than a guess, the same preset gives the same egg every time. Not approximately — actually.

🚶

Freedom from the stove

Set it and leave the kitchen. PotWatch handles the waiting, the counting and the shouting, and keeps calling until you come back.

⛰️

Correct in your kitchen

A built-in barometer adjusts the boiling point for your altitude and today's weather. A one-time calibration tunes it to your own stove.

🔥

It watches for trouble

If the water boils away, PotWatch stops and alarms instead of quietly cooking itself dry. A failed probe is reported, never faked.

🔋

Cordless

A Li-ion cell and USB-C charging. No cable trailing across the hob, nothing to plug in before cooking.

🛠️

Entirely yours

Every file is free: models, wiring, firmware. Don't like three minutes for a soft egg? Change one number and reflash. No patents, ever.

1 min
Benedict
3 min
Soft egg
5 min
Hard egg
≤ 2 h
Soup
≤ 6 h
Custom timer

// every countdown starts from the confirmed boil, not from the button press

Start here

Everything you need is on this site.

No kit to buy, nothing to subscribe to, no email address to hand over. The parts are ordinary, the enclosure prints on any 3D printer and the firmware flashes over USB.

Free and open

Build one. Change it. Share it.

Firmware under GPL v3, hardware and documentation under CC BY-SA 4.0. Nothing here is patented or trademarked, and it never will be.

See what you need