Long-grain Thai jasmine, known domestically as Khao Dawk Mali 105, contains an amylose content hovering between 12% and 19%. For comparison, traditional Indian basmati contains upwards of 24% amylose. Amylose gives grains structural rigidity during boiling. Low amylose, coupled with high amylopectin, produces soft, clingy textures that can turn gummy when over-hydrated.
This distinct starch profile explains why standard long-grain cooking directions fail. Jasmine kernels absorb liquid rapidly through micro-fissures in their outer aleurone layer. If excess water enters those fissures before the outer starches gelatinize, the rice matrix ruptures. You end up with a swollen, soggy mass instead of light, tender kernels.
Freshness also plays an operational role. Newly harvested "new crop" jasmine contains significantly more intrinsic moisture than aged stock. If your bag carries a current-year harvest stamp, trim your cooking water by roughly 5% to 8% to prevent the grains from softening past their ideal threshold.
