GravityMon, logged to your brew.
Point GravityMon's HTTP Post at BrewForge. Gravity and temperature from your DIY hydrometer land on the brew, with projected final gravity and a spunding forecast.
{
"name": "gravmon-fv3",
"ID": "e4b3a1",
"interval": 900,
"temperature": 10.2,
"temp_units": "C",
"gravity": 1.0175,
"corr-gravity": 1.0173,
"angle": 41.6,
"battery": 3.94,
"RSSI": -71,
"gravity-unit": "G"
}Temperature-corrected gravity, out of the box
GravityMon can send a temperature-corrected gravity next to the raw value. BrewForge picks up corr-gravity automatically when it is there, and converts °Plato to SG.
- Default iSpindel-style format, no custom template needed
- corr-gravity used when available
- °Plato and °F converted
- Gravity Offset in the device settings for calibration
Everything else about the batch, right next to it
The readings join the brew's fermentation log: gravity and temperature on one chart, projected final gravity and a spunding valve forecast, next to the recipe and your brew day measurements.
Set up in three steps
You need a calibrated GravityMon on your Wi-Fi. BrewForge shows these instructions again under Setup Instructions in the device menu.
- 1Add the device in BrewForgeOpen Devices → Add Device, choose GravityMon, name it and copy the webhook URL.
- 2Set up HTTP Post in GravityMonIn the GravityMon web UI go to Push → HTTP Post, paste the webhook URL and keep the iSpindel / default data format. Save and reboot.
- 3Attach it to a brewUse Attach to Brew in the device menu, or connect the device from the brew's Fermentation tab.
https://brewforge.sh/api/devices/webhook?key=3f9c2a7e-…Copy the whole URL, including the key.
Example payload
GravityMon's default format follows the iSpindel JSON. BrewForge reads corr-gravity (or gravity), temperature, battery and angle.
With "gravity-unit": "P" the gravity is read as °Plato. Custom templates that leave the unit out still work: values above the SG range are read as °Plato.
{
"name": "gravmon-fv3",
"ID": "e4b3a1",
"interval": 900,
"temperature": 10.2,
"temp_units": "C",
"gravity": 1.0175,
"corr-gravity": 1.0173,
"angle": 41.6,
"battery": 3.94,
"RSSI": -71,
"gravity-unit": "G"
}If readings don’t show up
- The device says "Awaiting first data…": check that GravityMon has Wi-Fi with internet access and has rebooted since you saved the push settings.
- Copy the complete webhook URL, including
?key=…. - Custom template? Send SG values or include the
gravity-unitfield. - Readings arrive but not on your brew: attach the device to the brew.
- Open Recent Data on the device to see the last payloads BrewForge received.
Hydrometer logging is included in every plan: Free (up to 20 brews), Basic and Pro.
Compare plansFAQ
GravityMon questions
Is BrewForge a GravityMon cloud service?
BrewForge is the place your GravityMon reports to: point GravityMon's HTTP Post push at your BrewForge webhook URL and the readings land on the brew the device is attached to.
Does BrewForge use the temperature-corrected gravity?
Yes. When GravityMon sends corr-gravity, BrewForge uses it instead of the raw gravity.
My GravityMon reports °Plato. Does that work?
Yes. Plato payloads are accepted and converted to SG. If you write your own template, either send SG values or include the gravity-unit field.
Do I need a paid plan for GravityMon?
No. Hydrometers can be connected on every plan, including Free (up to 20 brews).
Your next batch starts here.
Free for up to 20 brews. No credit card.