Organic brown sesame seeds are those that still have their exterior hull them. This hull or husk makes the seed harder and crunchier and tastes slightly bitter due to the oxalates in the hull. Most recipes that call for sesame seeds are calling for the unhulled variety. You can try making your tahini with the unhulled version if you prefer to have more calcium: unhulled sesame seeds 1 TBSP have approxiamtely 88 mg of calcium versus the hulled, in the same size, 5-10 mg. If you plan on sprouting the seeds which are rich in vitamines E, C, Magnesium, iron, calcium and more – you’ll want organic brown unhulled or organic black.