Quality & Specification
Understanding Bean Count and Size
How count per 100 g works, why a lower number means a larger bean, what size uniformity does in a canning process, and why size availability cannot be promised in advance.
· 6 min read
Beans are traded on size, and size in the bean trade is expressed as count per 100 g: the number of individual beans in a 100 gram sample. The convention catches people out at first because it runs backwards from intuition. A lower count means fewer beans make up 100 grams, which means each bean is larger. A higher count means a smaller bean.
Why buyers work to a band
No lot is uniform, so a contract specifies a band rather than a single figure — for example a range of counts within which the lot must fall. The width of that band matters as much as its position. A narrow band means more grading work and a higher reject fraction, and it costs more; a wide band is cheaper and produces a more variable product.
Where size uniformity really matters
For a buyer cooking beans domestically, a spread of sizes is a minor inconvenience. For an industrial canner it is a production problem. Canning is a fixed process: a batch is soaked for a set time and cooked to a set regime. Within that fixed process, small beans overcook and break up while large beans stay firm, so a lot with a wide size spread produces an inconsistent finished product even if every other parameter is met.
This is why navy bean and white bean specifications for canning typically use narrower bands than retail contracts for the same species, and why canners run their own soak and cook trial before approving an origin rather than relying on the written size band alone.
What determines the size a crop yields
- Variety — the genetic ceiling on seed size.
- Rainfall distribution during pod fill, which determines how completely the seed fills.
- Soil fertility and plant density.
- Growing zone and altitude.
- Harvest timing, since seed harvested early may not have filled completely.
Grading separates what grew; it does not create larger seed. That single fact explains why an honest supplier confirms size availability against the current crop instead of publishing a standing offer of a particular band. A season that finished poorly simply will not yield much material in the largest bands, and no amount of screening changes that.
Size conventions for other pulses
| Commodity | Convention | Example expression |
|---|---|---|
| Dry beans | Count per 100 g | A stated band of counts |
| Mung beans | Screen size in millimetres | 3.2 mm and above |
| Kabuli chickpeas | Calibrated size band | Contracted band, confirmed against the crop |
| Desi chickpeas | Screen size | Contracted screen, or approved sample |
| Pigeon peas | Not normally size graded | Screening removes undersize and broken only |
How size interacts with the other parameters in a bean contract. Dry beans hub