Milling is the process of removing the husk and splitting whole lentils to produce edible dal. The effectiveness of this process directly influences the final product’s quality. Dal milling involves several stages designed to clean, treat, and process pulses to enhance digestibility and reduce cooking time.
1. Cleaning and Grading
Initially, lentils are cleaned to remove impurities like stones, dust, and other foreign matter, using sieves and air classifiers. They are then sorted by size.
2. Pitting
Cleaned pulses are passed through emery rollers that crack or scratch the husk—a process called pitting. This step helps loosen the husk and allows better absorption of oil and moisture during further treatment.
3. Pretreatment
Pitted pulses are lightly coated with edible oil, such as linseed oil, which aids in loosening the husk even further.
4. Conditioning
The oil-treated pulses undergo alternating wetting and drying—often sun-dried for a few days—to adjust moisture levels and prepare them for dehusking.
5. Dehusking and Splitting
Using emery roller machines (gota), husks are removed, and the pulses are split in half. Multiple passes are usually required to achieve complete dehusking.
6. Polishing
To enhance visual appeal, split dal may be polished using oil, water, or other methods like nylon, leather, or velvet polishing. Although it adds market value, polishing is not considered nutritionally beneficial.
7. Separation and Grading
Finally, the milled dal is sorted using sieves to separate whole dal, broken pieces, and husk, ensuring a uniform end product.
Dal Milling Process: Steps from Whole Pulses to Edible Dal
