High broken-rice levels are not automatically a machine-part problem.
Before changing a screen, drum or machine, check the paddy itself.
1. Check paddy moisture
IRRI recommends approximately 13–14% moisture content for milling. Paddy that is too dry becomes brittle and breaks more easily, while unsuitable moisture conditions can also reduce milling performance.
This should be one of the first checks.
2. Check whether the grain was already cracked
Rice can develop cracks before it reaches the mill.
Possible causes include:
- poor drying
- repeated wetting and drying
- harvest damage
- poor storage
- immature grain
A milling machine cannot turn damaged paddy back into sound grain.
3. Check milling pressure and adjustment
Too much pressure can increase:
- friction
- temperature
- grain damage
- breakage
The correct adjustment depends on the machine and paddy condition.
4. Check worn components
Inspect:
- screen / sieve
- milling drum
- roller
- bearings
- other milling-chamber components
Worn parts can change the way grain moves through the chamber.
5. Understand the limitation of the milling system
The problem may not always be maintenance.
Traditional Engelberg-type single-stage mills apply relatively aggressive milling action and are known for higher grain breakage compared with more modern multi-stage systems.
IRRI reports typical head-rice recovery for a single-stage village Engelberg mill at only around 15–30% of paddy weight, versus approximately 40–50% for compact two-stage mills under its example conditions.
Therefore, there is a point where adjustment cannot fully overcome the underlying milling technology.
Repair or upgrade?
Repair your existing machine if:
- breakage recently increased
- a component is clearly worn
- previous rice quality was acceptable
Consider another milling system if:
- high breakage has always been normal
- buyers are demanding better whole-grain quality
- broken rice is reducing your selling price
- repeated adjustment does not solve the problem