diff --git a/README.md b/README.md
index 65827f5..2d151ef 100644
--- a/README.md
+++ b/README.md
@@ -128,8 +128,11 @@ environment (`$WORKON_HOME`/`$BREWPI_HOME`) on a Raspberry Pi-style deployment.
 
 ## Mash schedules
 
-Files under `sude/` describe a brew's mash schedule ("Sud"): pot weight,
-malt/water weights, and a flat `schedule` list of steps, each either:
+Files under `sude/` describe a brew's mash schedule ("Sud"): `pot_mass`,
+`pot_material`, `grain_mass`, `water_mass` (used by `Sud.derive_plant_params()`
+to compute a lumped thermal mass/specific-heat pair for `Pot`'s `M`/`C`, e.g.
+in `scripts/demos/sud/demo_sud.py`, instead of hand-tuning them), and a flat
+`schedule` list of steps, each either:
 
 - `"type": "heat"` — ramp to `temp` at `rate` (°C/min), or
 - `"type": "hold"` — hold the current target for `duration` seconds (omit