Parboiling is the step that decides most of what a buyer eventually receives, and it happens before the paddy is milled at all. This note walks through the sequence as it runs at Ghentugachhi, and what each stage is actually controlling.
1. Intake and identification
Paddy arrives at the mill and is weighed in over the weighbridge. Each intake is identified lot-wise so it can be traced through processing, and is assessed on arrival before it is taken into process. Nothing is blended into a running lot after the fact.
2. Pre-cleaning
Straw, dust, stones and foreign matter are separated from the paddy first. Cleaning before soaking matters more than it sounds: anything left in at this stage carries water, takes up boiler heat, and ends up as a defect the colour sorter has to remove later.
3. Soaking
Cleaned paddy is soaked in water on the INDUSS system. The grain absorbs moisture through the husk, which is still intact — this is what separates parboiling from anything done to milled rice. Soaking time and water temperature are the first two variables that change the finished colour.
4. Steaming
The soaked paddy is steamed. Heat gelatinises the starch inside the kernel while the husk holds the grain together. This is the step that hardens the rice, seals cracks that would otherwise break during milling, and drives some of the bran-layer vitamins inward. A longer, hotter parboil gives a harder, darker grain; a lighter one stays paler.
5. Controlled drying
Parboiled paddy is dried back to milling condition. Drying is where a lot of yield is won or lost — dried too fast and the kernel fissures, so the mill gets brokens it would not otherwise have had. The dryers and the process heat run on a Thermax boiler fired with husk from the mill’s own processing.
6. Milling, grading and sorting
Only now does the paddy reach the Satake line: de-husking, then whitening and polishing to the required degree, then size grading, then optical colour sorting on the Sortex. Milled rice is checked before packing, and packed according to confirmed buyer requirements.
What this means when you specify
Because soaking, steaming and drying all move the finished colour and hardness, “parboiled” on its own is not a specification. Tell us the colour range your market accepts, the maximum broken percentage and the moisture limit, and the parboil is run to suit. Send those with your enquiry and the specification is confirmed in writing before production is scheduled.
